Top 150 Computer Awareness Terms for Bank Exams
Master the 150 most important Computer Awareness terms frequently asked in Bank, Insurance, and Regulatory Body examinations. This comprehensive resource covers topics ranging from computer fundamentals, hardware, software, operating systems, networking, internet, cybersecurity, databases, cloud computing, and emerging technologies. Each term is explained in a simple, exam-oriented manner with concise definitions and key facts, making it ideal for conceptual clarity, quick revision, and last-minute preparation.
Software versions verified August 2026. Confirm the current Windows, macOS, Android and Office versions before your exam, as these update every year.
How to use this glossary
Read each term top to bottom in the order given, because the list follows a learning order in which earlier terms support later ones. Tap a card to expand its full explanation, and tick the box on the left rail once you are confident, so the mastery meter in the control bar tracks your progress.
Use the search box and the chapter and level filters to focus on weak areas, drill the flashcards to test recall from the definition alone, and finish with the ten question self test. Your ticks are saved in your own browser, so your progress stays even if you close the page.
Why these 150 terms
Computer awareness is a scoring section in the mains stage of NABARD Grade A, RRB PO and Clerk, IBPS and SBI exams, yet it is often left to the last minute. The terms here were chosen because they recur across previous papers and cover the full official syllabus, from computer history and hardware to networking, databases, security and the fast growing area of artificial intelligence.
Rather than an alphabetical dump, the entries are grouped into twelve chapters and ordered so that foundational ideas such as the CPU, memory units and the OSI model come before the terms that build on them. Volatile facts, such as the latest operating system and office versions, have been checked against current sources and are flagged for you to verify again close to your exam date.
Each entry keeps the same tight shape: a single sentence definition you can recall under pressure, a three to five sentence explanation with an Indian example, and two related terms you can jump to. This structure is designed for revision and recall, not just reading.
Table of contents
- 01Introduction and History of Computers001-012 · 12
- 02Generations and Types of Computers013-024 · 12
- 03Computer Architecture and Components025-038 · 14
- 04Input and Output Devices039-050 · 12
- 05Memory and Storage051-064 · 14
- 06Software and Programming065-076 · 12
- 07Operating Systems077-086 · 10
- 08Microsoft Office Suite087-098 · 12
- 09Computer Networks and Internet099-118 · 20
- 10Database Management System119-128 · 10
- 11Computer Security and Malware129-140 · 12
- 12Artificial Intelligence, ML and Generative AI141-150 · 10
Introduction and History of Computers
ENTRIES 001 TO 012
- CA-001
Computer
BasicDefinition. An electronic device that accepts data, processes it under a set of stored instructions, and produces meaningful information as output.A computer follows the input, process, output and storage cycle to convert raw data into usable information. It is a general purpose machine because the same hardware can run a banking application, a spreadsheet or a game just by changing the software. In Indian competitive exams the computer is usually described as fast, accurate, reliable and capable of storing large volumes of data without fatigue. Remember that a computer has no intelligence of its own and only does what its program instructs, which is why the term GIGO, garbage in garbage out, is often tested.
Related - CA-002
Data and Information
BasicDefinition. Data is raw unprocessed facts and figures, while information is processed, organised data that carries meaning for the user.For example, a list of account numbers with balances is data, but a bank statement that summarises a customer's monthly transactions is information. The computer performs data processing to convert one into the other. In exams the distinction is a frequent one-mark question, so fix it firmly: data is the input, information is the meaningful output. A collection of related information stored for reuse forms a database.
Related - CA-003
Abacus
BasicDefinition. The earliest known manual calculating device, using beads on rods to perform addition and subtraction, developed in China around 2600 BC.The abacus is regarded as the first counting tool and is a favourite history question in RRB and clerk exams. It has no electronic parts and depends entirely on the human operator moving beads. Its importance is historical, as it marks the beginning of humanity's effort to mechanise calculation, a journey that later led to Napier's Bones and the Pascaline. Candidates should link it firmly to China and to the year 2600 BC.
Related - CA-004
Napier's Bones
IntermediateDefinition. A manual calculating aid of numbered rods invented by John Napier around 1614 to 1617 to simplify multiplication and division.John Napier, a Scottish mathematician, is also credited with the concept of logarithms, which underpins the design of these rods. Napier's Bones let a user break multiplication into simpler additions by reading off partial products from the rods. This device is an important stepping stone between the abacus and mechanical calculators like the Pascaline. In exams the name John Napier and the association with multiplication are the tested points.
Related - CA-005
Pascaline
IntermediateDefinition. A mechanical calculator built by Blaise Pascal in 1642 with an eight digit capacity, able to add and subtract using geared wheels.The Pascaline is often called the first mechanical calculator that worked through interlocking gears. Blaise Pascal designed it to help his father, a tax official, with arithmetic. Its eight digit capacity and the year 1642 are commonly asked in RRB PO and clerk papers. It paved the way for Leibniz and later for Charles Babbage's more ambitious engines.
Related - CA-006
Difference Engine and Analytical Engine
IntermediateDefinition. Machines designed by Charles Babbage, the Difference Engine in 1822 for tables and the Analytical Engine in 1834 as a programmable general purpose computer.Charles Babbage is honoured as the Father of the Computer for conceiving the Analytical Engine, which contained the ideas of an input, a store, a mill for processing and an output. Augusta Ada Byron, known as Ada Lovelace, wrote the first program for this engine and is remembered as the first computer programmer. These two facts, Babbage as father and Ada as first programmer, are among the most frequently asked in bank exams. The engines were never fully built in his lifetime but their logic anticipated the modern computer.
Related - CA-007
Tabulating Machine
IntermediateDefinition. An electromechanical machine built by Herman Hollerith in 1890 that read data from punched cards to speed up the United States census.Hollerith's punched card system could sort and count census records far faster than manual methods. The company he founded later became International Business Machines, or IBM, in 1924, a link worth memorising. The punched card remained a common input medium right up to the early mainframe era. For exams, connect Herman Hollerith with the census, punched cards and the origins of IBM.
Related - CA-008
ENIAC
IntermediateDefinition. The Electronic Numerical Integrator and Computer, developed between 1943 and 1946, was the first general purpose electronic computer, based on decimal numbers.ENIAC was created by J. Presper Eckert and John Mauchly and used thousands of vacuum tubes, making it a first generation machine. Unlike later binary computers, it worked with decimal numbers. It was enormous, power hungry and generated a great deal of heat, which is a typical feature of vacuum tube computers. In exams remember the full form, the inventors Eckert and Mauchly, and that it was the first general purpose electronic computer.
Related - CA-009
EDVAC and Stored Program Concept
AdvancedDefinition. EDVAC, an early binary stored program computer of 1949, embodied John von Neumann's idea that instructions and data are held together in the same memory.The stored program concept means a computer keeps both the program and the data in memory, so it can be reprogrammed without rewiring. This idea, credited to John von Neumann, is the foundation of the von Neumann architecture used by almost every modern computer. EDVAC was binary rather than decimal, unlike ENIAC, which is a common comparison in exams. Britain's EDSAC of 1949, built by Maurice Wilkes, is often paired with EDVAC as the first fully operational stored program computer.
Related - CA-010
UNIVAC
IntermediateDefinition. The Universal Automatic Computer, released in 1951, was the world's first commercially available computer, marking the start of the computer industry.UNIVAC moved computing out of the laboratory and into business and government use, which is why it is called the first commercial computer. It was developed by the team behind ENIAC after they formed the first computer company, EMCC. For exams the two facts to fix are the year 1951 and the description as the world's first commercial computer. It belongs to the first generation of vacuum tube machines.
Related - CA-011
IPOS Cycle
BasicDefinition. The Input, Process, Output and Storage cycle describes the four basic operations every computer performs on data.Input devices such as a keyboard feed data in, the central processing unit processes it, output devices such as a monitor present the result, and storage keeps data for later use. This cycle is the simplest model of how a computer works and appears often in clerk level papers. It helps candidates classify any device by asking which stage of the cycle it belongs to. A scanner is input, a printer is output and a hard disk is storage.
Related - CA-012
Moore's Law
AdvancedDefinition. An observation by Gordon Moore that the number of transistors on a chip roughly doubles about every two years, raising computing power steadily.Gordon Moore co-founded Intel in 1968 with Robert Noyce, and his law has guided the electronics industry for decades. It explains why processors keep getting faster and cheaper while shrinking in size, a trend that drove the shift from large mainframes to today's smartphones. Although physical limits are now slowing the pace, the law remains a standard exam fact linked to Moore and Intel. Candidates should treat it as an observation about trends, not a law of physics.
Related
Generations and Types of Computers
ENTRIES 013 TO 024
- CA-013
First Generation Computers
IntermediateDefinition. Computers from about 1945 to 1955 that used vacuum tubes for circuitry and magnetic drums for memory, exemplified by ENIAC, EDVAC and UNIVAC.Vacuum tube machines were very large, consumed heavy power and produced a lot of heat, so they needed constant cooling. They used machine language and had limited memory of a few thousand bits. Reliability was low because the tubes burned out frequently. For exams, tie the first generation to vacuum tubes and the machines ENIAC, EDVAC, EDSAC and UNIVAC.
Related - CA-014
Second Generation Computers
IntermediateDefinition. Computers from about 1955 to 1965 built with transistors, which replaced vacuum tubes and used magnetic core memory for primary storage.The transistor was invented by Bardeen, Brattain and Shockley at Bell Laboratories, and it made computers smaller, faster and more reliable. These machines used assembly language and early high level languages. Examples include the IBM 700 and 7000 series and IBM 1401. In exams remember the key shift, vacuum tubes to transistors, as the defining feature of this generation.
Related - CA-015
Third Generation Computers
IntermediateDefinition. Computers from about 1965 to 1971 that used integrated circuits, invented by Jack Kilby and Robert Noyce, along with keyboards and monitors.An integrated circuit packs many transistors onto a single silicon chip, which greatly reduced size and cost while increasing speed. This generation introduced multiprogramming and the familiar keyboard and monitor combination. The IBM 360 and 370 series are standard examples. For exams, connect the third generation with the integrated circuit and the names Kilby and Noyce.
Related - CA-016
Fourth Generation Computers
IntermediateDefinition. Computers from about 1971 onward built around the microprocessor, which places the entire central processing unit on a single chip using VLSI technology.Very Large Scale Integration, or VLSI, allowed millions of transistors on one chip, giving rise to the personal computer. The Intel 4004 of 1971 was the first microprocessor and defines this generation. Time sharing, real time and network operating systems appeared during this period. Examples include the Apple Macintosh and the IBM PC, both frequently tested.
Related - CA-017
Fifth Generation Computers
IntermediateDefinition. Present day computers, from about 1990 onward, based on Ultra Large Scale Integration and artificial intelligence, aiming at parallel processing and natural interaction.This generation focuses on artificial intelligence features such as robotics, neural networks and expert systems. It uses ULSI chips and pursues parallel processing and supercomputing advances. Laptops, notebooks, ultrabooks and chromebooks belong here. In exams the fifth generation is linked to artificial intelligence, which now includes machine learning and generative AI covered later in this glossary.
Related - CA-018
Analog, Digital and Hybrid Computers
BasicDefinition. Analog computers measure continuous physical quantities, digital computers process discrete binary data, and hybrid computers combine features of both.An analog computer, introduced in concept by Lord Kelvin, represents data as a continuous variable such as voltage, like a mercury thermometer. A digital computer, the everyday type, works with the binary digits 0 and 1, as in a digital watch. A hybrid computer blends both and is common in hospitals, for example an ICU monitor that senses analog signals and displays digital readings. This three way classification by technology is a reliable exam question.
Related - CA-019
Microcomputer
BasicDefinition. A small, relatively inexpensive computer built around a microprocessor and designed for personal or office use, such as a desktop or laptop.Microcomputers have the lowest storing and processing capacity among the size based categories but are the most common because they are affordable. A home desktop, a laptop and a tablet are all microcomputers. They form the base of the size classification, above which sit minicomputers, mainframes and supercomputers. In exams the microcomputer is defined by personal use and a single microprocessor.
Related - CA-020
Minicomputer
IntermediateDefinition. A mid sized computer more powerful than a microcomputer, offering faster speeds and larger storage, able to serve from a few to a few hundred users.Minicomputers were popular in medium organisations and can act as servers supporting from 2 to about 200 users. They sit between the microcomputer and the mainframe in the size hierarchy. In modern usage powerful servers have largely replaced traditional minicomputers, but the category still appears in exams. Remember the multi user capability as the key distinction from a microcomputer.
Related - CA-021
Mainframe Computer
IntermediateDefinition. A large, powerful computer with very high memory and processing speed, used as a central server that can support thousands of users at once.Banks, insurance companies and railways in India use mainframes for high volume transaction processing, for example a bank's core banking system. They are prized for reliability and the ability to handle enormous workloads continuously. They rank above minicomputers and just below supercomputers in the size classification. For exams, associate the mainframe with thousands of concurrent users and large enterprise use.
Related - CA-022
Supercomputer
IntermediateDefinition. The fastest and most powerful class of computer, used for highly complex tasks such as weather forecasting, scientific research and weapon design.Supercomputers achieve their speed through parallel processing across many processors. India's PARAM series, developed by C-DAC, and the Pratyush and Mihir systems used for weather forecasting are important national examples for exams. They are employed where extreme computation is needed, not for everyday office work. Fix the phrase specific complex applications and remember the Indian PARAM series.
Related - CA-023
Server and Workstation
IntermediateDefinition. A server is a dedicated computer that serves requests from other computers, while a workstation is a high performance computer usually serving a single user.A server, such as a web server or file server, provides resources like files, printing or web pages to many client machines over a network. A workstation is a powerful single user machine used for demanding tasks like engineering design or video editing. The two are frequently contrasted in exams by their user count, many for a server and one for a workstation. Both are types of computers defined by their role rather than only their size.
Related - CA-024
Embedded System
AdvancedDefinition. A computer system with a dedicated function built into a larger device, performing a specific task rather than acting as a general purpose computer.Embedded systems run inside washing machines, cars, microwave ovens, ATMs and traffic signals, doing one job reliably. Unlike a personal computer, they are not meant to be reprogrammed by the user for many purposes. They often combine a microcontroller with fixed firmware. In exams the defining idea is a dedicated function within a larger system, so an ATM's control unit is a classic example.
Related
Computer Architecture and Components
ENTRIES 025 TO 038
- CA-025
Central Processing Unit (CPU)
BasicDefinition. The CPU, often called the brain of the computer, controls all operations and carries out the instructions contained in a program.The CPU is made up of the control unit, the arithmetic logic unit and a set of registers. It fetches instructions from memory, decodes them and executes them, directing every other component. It is also known as the processor and, in a microcomputer, sits on a single microprocessor chip. For exams remember that CU and ALU together with registers form a complete CPU.
Related - CA-026
Control Unit (CU)
IntermediateDefinition. The part of the CPU that directs and coordinates all operations by fetching and decoding instructions and telling other units what to do.The control unit does not process data itself but acts as a manager, sending control signals across the system bus. It fetches each instruction from memory, decodes it and then commands the arithmetic logic unit or memory to act. Together with the ALU and registers it completes the CPU. In exams the CU is described as the part that controls and coordinates, in contrast to the ALU which calculates.
Related - CA-027
Arithmetic Logic Unit (ALU)
IntermediateDefinition. The part of the CPU that performs all arithmetic operations such as addition and all logical comparisons such as greater than or equal to.The ALU is a core component of the CPU and handles the actual number crunching and decision comparisons. Arithmetic covers addition, subtraction, multiplication and division, while logic covers comparisons that produce true or false results. It works closely with registers that hold the operands and results. For exams pair the ALU with calculation and comparison, distinct from the control unit's coordinating role.
Related - CA-028
Register
AdvancedDefinition. A small, very fast temporary storage location inside the CPU that holds data, addresses or instructions during processing.Registers sit at the very top of the memory hierarchy and are faster than cache or main memory because they are inside the processor. Examples include the accumulator, which holds the result of an arithmetic or logic operation, and the program counter. They are limited in number and size but essential for high speed operation. In exams the register is described as the fastest storage, more quickly accessible than main memory.
Related - CA-029
Motherboard
BasicDefinition. The main circuit board of a computer that holds and connects the CPU, memory and other core components together.The motherboard provides the sockets, slots and buses through which every part of the system communicates. It houses the CPU socket, RAM slots, expansion card slots and ports, along with the BIOS chip. Everything from the processor to the keyboard connector links back to the motherboard. For exams it is simply the main board that holds the internal components of the computer.
Related - CA-030
Microprocessor
IntermediateDefinition. A single silicon chip that contains the complete central processing unit, integrating the control unit, arithmetic logic unit and registers.The microprocessor defines fourth generation computing and made the personal computer possible. Intel's 4004 in 1971 was the first, followed by the 8008 and later families. Its speed is measured by clock speed in gigahertz and by word length in bits. In exams the microprocessor is the CPU on one chip, and the 4004 as the first is a common fact.
Related - CA-031
System Bus
AdvancedDefinition. A set of parallel wires that carries data, addresses and control signals between the CPU, memory and input output devices.There are three types of bus: the address bus that carries memory locations, the data bus that carries the actual data, and the control bus that carries command signals. The width of the data bus affects how much data can move at once, so a wider bus improves performance. All buses run across the motherboard connecting the major components. For exams remember the three bus types and their separate roles.
Related - CA-032
Ports
BasicDefinition. Connecting sockets on the outside of the system unit into which cables of different devices are plugged.Common examples include the USB port, HDMI port for display, and the audio jack. Ports allow external devices such as a keyboard, printer or pen drive to communicate with the computer. Each port type has a defined shape and standard so that only compatible cables fit. In exams a port is simply a socket outside the system for connecting cables.
Related - CA-033
Clock Speed
IntermediateDefinition. The rate at which a CPU executes basic operations, measured in hertz, commonly gigahertz, where higher values mean a faster processor.Clock speed counts how many cycles the processor completes each second, so a 3 gigahertz CPU performs about three billion cycles per second. It is one of the main indicators of processing power, alongside the number of cores and cache size. It is sometimes called clock rate. For exams, remember the unit hertz and that a higher clock speed generally means faster processing.
Related - CA-034
Cache Memory
AdvancedDefinition. A very high speed and expensive memory placed between the CPU and main memory to store frequently accessed data and speed up processing.Because main memory is slower than the CPU, cache reduces the mismatch by keeping recently or frequently used data close to the processor. It sits above main memory in the memory hierarchy and is smaller but much faster. Modern processors use several levels of cache, often labelled L1, L2 and L3. In exams cache is defined as a small, fast buffer that speeds up memory retrieval between the CPU and main memory.
Related - CA-035
Graphics Processing Unit (GPU)
AdvancedDefinition. A specialised processor designed to handle image, video and graphics calculations rapidly using many cores working in parallel.While the CPU handles general tasks, the GPU excels at the parallel maths needed for rendering graphics, gaming and video. In recent years GPUs have become central to artificial intelligence, since training machine learning and deep learning models relies on their parallel power. This link between GPUs and AI is increasingly relevant for current affairs style questions. For exams remember the GPU as the graphics and parallel processing engine now vital to AI workloads.
Related - CA-036
BIOS
IntermediateDefinition. The Basic Input Output System, firmware stored in ROM that starts the computer and lets the operating system interact with hardware.When a computer is switched on, the BIOS runs first, performs a power on self test known as POST, and then loads the operating system through the boot process. Being stored in read only memory, it is non volatile and remains available even without power. Modern systems often use UEFI, a newer replacement, but exams still ask about BIOS. Fix the two facts: BIOS is stored in ROM and it starts the boot sequence.
Related - CA-037
Expansion Cards
IntermediateDefinition. Circuit boards added to the motherboard to give the computer extra capabilities, such as sound cards, video cards and network interface cards.A sound card handles audio, a video or graphics card drives the display, and a network interface card, or NIC, lets the computer join a network. These cards plug into expansion slots on the motherboard. They extend a basic system without replacing the whole machine. In exams the three commonly listed cards are sound card, video card and NIC.
Related - CA-038
Word Length
AdvancedDefinition. The number of bits a CPU can process as a single unit, such as 32 bit or 64 bit, which affects speed and addressable memory.A larger word length lets the processor handle more data per operation and address more memory, which is why 64 bit systems can use far more RAM than 32 bit ones. The Intel 4004 was a 4 bit processor, the 8008 was 8 bit, showing how word length grew over generations. It is closely tied to performance along with clock speed. For exams, connect word length to the number of bits processed together and to 32 bit versus 64 bit systems.
Related
Input and Output Devices
ENTRIES 039 TO 050
- CA-039
Input Device
BasicDefinition. Any peripheral used to feed data or control signals into a computer for processing, such as a keyboard, mouse or scanner.Input devices form the first stage of the IPOS cycle by supplying raw data to the system. Common examples in exams include the keyboard, mouse, scanner, joystick, microphone, OMR, OCR and MICR readers. Some devices, like a touch screen, act as both input and output. For exams, be ready to classify a given device as input, output or storage.
Related - CA-040
Keyboard
BasicDefinition. The primary text input device, arranged in the QWERTY layout, used to enter letters, numbers, symbols and commands into a computer.A standard keyboard has 104 keys, including alphabet, number, function keys F1 to F12, modifier keys such as Ctrl and Alt, and navigation keys. The number pad on the right has 17 keys. Keyboards connect through USB or Bluetooth. For exams, remember the 104 key figure and the QWERTY arrangement named after the first six letters.
Related - CA-041
Mouse
BasicDefinition. A pointing input device used to move a cursor and select objects on the screen, commonly of the optical or mechanical type.The mouse was invented by Douglas Engelbart in 1964 and is a graphical user interface device, since it is most useful with a GUI rather than a command line. It comes in wired and wireless forms, and optical mice have largely replaced the older mechanical ball design. A trackball and a touchpad are related pointing devices. For exams, connect the mouse with pointing, with Engelbart, and with the graphical user interface.
Related - CA-042
Scanner
BasicDefinition. An input device that reads a printed image or document and converts it into a digital file that the computer can store or edit.Scanners connect through USB and come in flatbed, sheet fed and handheld types. A flatbed scanner uses a flat glass surface, a sheet fed scanner pulls paper through like a fax, and a handheld scanner is dragged across the page. Scanners are widely used in offices for digitising documents. For exams, know the three scanner types and that a scanner turns a physical image into a digital file.
Related - CA-043
Optical Mark Recognition
IntermediateDefinition. OMR is a technology that reads marks made by a pen or pencil on printed forms, widely used to evaluate multiple choice answer sheets.In India OMR is familiar from competitive exam answer sheets, where candidates darken bubbles that a machine then reads. It captures human marked data from forms and surveys quickly and accurately. It reads the presence and position of marks rather than the characters themselves, which distinguishes it from OCR. For exams, link OMR firmly with objective answer sheets and bubble marking.
Related - CA-044
Magnetic Ink Character Recognition
AdvancedDefinition. MICR is a character recognition technology used mainly by banks to process cheques quickly using special magnetic ink printed characters.The MICR code line at the bottom of an Indian cheque encodes the cheque number, bank branch and account details in magnetic ink. Because it is highly reliable and hard to forge, it streamlines clearing and processing of cheques. This is one of the most important banking related computer topics for RRB, NABARD and bank PO exams. Fix the association of MICR with cheques and with the banking industry.
Related - CA-045
Optical Character Recognition
IntermediateDefinition. OCR is software that works with a scanner to convert printed or handwritten characters in an image into editable digital text.Unlike OMR, which only detects marks, OCR actually recognises letters and numbers and turns them into machine readable text. It is used to digitise books, forms and documents so their content can be searched or edited. Many banking and government workflows use OCR to read printed information automatically. For exams, contrast OCR, which reads characters, with OMR, which reads marks, and MICR, which reads magnetic ink.
Related - CA-046
Barcode and QR Code
IntermediateDefinition. A barcode is a machine readable pattern of lines encoding data, while a QR code is a two dimensional matrix of dots holding much more information.A barcode reader uses optical technology such as infrared light to scan product codes at shops. A QR code, short for quick response code, can be scanned by a smartphone camera and is now central to India's UPI digital payments. Both convert a visual pattern into numbers or text for the computer. For exams, remember barcode as one dimensional lines and QR as a two dimensional dot matrix widely used in Indian payments.
Related - CA-047
Output Device
BasicDefinition. Any hardware that converts processed information into a human readable form such as text, graphics, audio or video.Output devices form the third stage of the IPOS cycle, presenting results to the user. Common examples include the monitor, printer, projector, plotter and speakers. A monitor and projector give visual output, while speakers give sound output. For exams, be able to separate output devices from input and storage devices in a mixed list.
Related - CA-048
Monitor and Display Types
IntermediateDefinition. The monitor is the standard visual output device, available in CRT, LCD and LED types, with resolution standards from VGA up to SVGA.CRT, the cathode ray tube, is the bulky older display, while LCD, liquid crystal display, and LED, light emitting diode, are the thin modern types. Resolution and colour depth improve from CGA and EGA up through VGA, XGA and SVGA. Monitors can be monochrome or colour. For exams, know the display technologies and that SVGA offers a higher resolution than VGA.
Related - CA-049
Printer Types
IntermediateDefinition. Printers convert soft copy to hard copy and are grouped into impact printers, which strike the paper, and non impact printers, which do not.Impact printers such as dot matrix, daisy wheel and line printers use a hammer and ribbon striking the paper. Non impact printers such as inkjet, laser and thermal printers do not strike the paper and are quieter and faster. Colour printing uses the CMYK model, cyan, magenta, yellow and key or black. For exams, correctly place dot matrix as impact and laser and inkjet as non impact.
Related - CA-050
Plotter
IntermediateDefinition. An output device that produces high quality, large and accurate drawings, commonly used in engineering and architecture through CAD applications.Unlike a printer, a plotter draws continuous lines and is ideal for maps, banners, building plans and vehicle part designs. It is used with computer aided design and computer aided manufacturing software. Plotters handle much larger paper sizes than ordinary printers. For exams, link the plotter with CAD, engineering drawings and large format output.
Related
Memory and Storage
ENTRIES 051 TO 064
- CA-051
Bit and Byte
BasicDefinition. A bit is the smallest unit of data, holding a 0 or a 1, while a byte is a group of 8 bits and represents one character.All data inside a computer is ultimately stored as bits, the binary digits 0 and 1. Four bits make a nibble and eight bits make a byte, which can store a single letter such as A. Larger amounts of storage are measured in multiples of the byte. For exams, memorise that 1 byte equals 8 bits and 1 nibble equals 4 bits.
Related - CA-052
Memory Units
BasicDefinition. Storage is measured in multiples of the byte, where 1024 bytes make a kilobyte and each higher unit is 1024 times the previous one.The sequence runs kilobyte, megabyte, gigabyte, terabyte, petabyte and beyond, each step being 1024 of the one below. So 1024 KB make 1 MB and 1024 MB make 1 GB. These conversions are among the most reliable one-mark questions in clerk exams. Fix the multiplier 1024 and the order of the units firmly in memory.
Related - CA-053
Primary Memory
BasicDefinition. Also called main memory, it is the internal storage directly accessed by the CPU, holding the data and instructions currently in use.Primary memory is fast and includes RAM and ROM. It is directly reachable by the processor, unlike secondary storage, which the CPU cannot access directly. It is often volatile in the case of RAM, meaning its contents are lost when power is switched off. For exams, define primary memory as the fast internal memory the CPU works with right now.
Related - CA-054
Secondary Memory
BasicDefinition. Also called auxiliary or external memory, it stores data permanently, is slower than primary memory, and is not directly accessed by the CPU.Hard disks, pen drives, CDs and DVDs are secondary storage, used to keep programs and files even after the power is off. It offers far larger capacity than primary memory but at slower speed. Data must first be moved into primary memory before the CPU can process it. For exams, contrast secondary memory, permanent and large, with primary memory, fast and directly used by the CPU.
Related - CA-055
Random Access Memory (RAM)
BasicDefinition. A volatile primary memory that stores data and instructions the computer is currently using, losing its contents when power is turned off.RAM is called read write memory because information can be both read from and written to it freely. It is volatile, so anything not saved to secondary storage is lost on shutdown. Its two main types are static RAM and dynamic RAM. For exams, the key phrases are volatile, temporary and read write memory.
Related - CA-056
SRAM and DRAM
AdvancedDefinition. Static RAM uses flip flops and is fast without needing refresh, while dynamic RAM uses capacitors, is slower and must be refreshed continually.SRAM retains data as long as power is supplied and needs no periodic refresh, which makes it fast but expensive, so it is used for cache. DRAM stores each bit in a tiny capacitor that leaks charge, so it must be refreshed thousands of times a second, making it slower but cheaper for main memory. This trade off explains why systems use a little SRAM cache and a lot of DRAM. For exams, pair SRAM with flip flops and speed, DRAM with capacitors and refresh.
Related - CA-057
Read Only Memory (ROM)
BasicDefinition. A non volatile primary memory that permanently stores essential instructions such as the BIOS, retaining its contents even without power.ROM holds the startup instructions the computer needs before the operating system loads, which is why the BIOS resides in ROM. Being non volatile, it keeps its data permanently. Its programmable variants are PROM, EPROM and EEPROM. For exams, remember ROM as non volatile, permanent memory that stores the BIOS.
Related - CA-058
PROM, EPROM and EEPROM
AdvancedDefinition. Three types of programmable ROM: PROM can be written once, EPROM can be erased by ultraviolet light, and EEPROM can be erased electrically.PROM is manufactured blank and programmed once by the user, unlike ordinary ROM which is set during manufacture. EPROM can be wiped clean by exposure to ultraviolet light and reprogrammed, so it is also called UVEPROM. EEPROM can be erased and rewritten using an electrical charge, and modern flash memory is built on this idea. For exams, match each type to its erasing method: none, ultraviolet, and electrical.
Related - CA-059
Memory Hierarchy
AdvancedDefinition. The arrangement of computer memory by speed and cost, from fast registers and cache down to slower main memory and secondary storage.At the top sit registers inside the CPU, the fastest and smallest, followed by cache, then main memory, and finally large but slow secondary storage. As you move down the hierarchy, speed and cost per unit fall while capacity rises. This design balances performance against price. For exams, order the levels correctly: registers, cache, RAM, then secondary storage.
Related - CA-060
Virtual Memory
AdvancedDefinition. A technique that uses part of the hard disk as an extension of RAM, allowing the system to run programs larger than the physical memory.When RAM is full, the operating system borrows space from secondary storage to hold data temporarily, which is called virtual memory or extended RAM. This lets more or larger applications run at once, though disk access is much slower than real RAM. Excessive reliance on it can slow the computer, a condition known as thrashing. For exams, define virtual memory as extra memory borrowed from the hard disk beyond the physical RAM.
Related - CA-061
Magnetic Storage
IntermediateDefinition. Secondary storage that records data as magnetised spots on a surface, including the hard disk drive and the older floppy disk.The hard disk drive, or HDD, stores large volumes on spinning magnetic platters and is the traditional main storage of a computer. The floppy disk, with a capacity of about 1.44 MB, was an early portable magnetic medium now obsolete. Magnetic tape provides sequential access and is used for backup. For exams, know the HDD as a random access magnetic disk and the floppy's 1.44 MB capacity.
Related - CA-062
Optical Storage
IntermediateDefinition. Secondary storage that reads and writes data using laser light, including the CD, DVD, Blu-ray and holographic discs.A CD holds about 700 MB, a DVD about 4.7 GB, and a Blu-ray disc 25 GB single layer or 50 GB double layer. The holographic versatile disc, or HVD, offers even higher capacity. Each type comes in read only, recordable and rewritable forms. For exams, memorise the capacity ladder from CD to DVD to Blu-ray.
Related - CA-063
Flash Memory and SSD
IntermediateDefinition. Flash memory is non volatile electronic storage used in pen drives and memory cards, and the solid state drive, or SSD, uses it to replace the hard disk.Flash memory is built on EEPROM technology and retains data without power, making it ideal for portable storage. Memory cards include the MMC, multimedia card, and the SD card, secure digital, which comes in SDSC, SDHC, SDXC and SDUC capacity classes. The SSD uses flash chips instead of spinning platters, giving much faster and more durable storage than a hard disk. For exams, link flash memory with pen drives and note that SSDs are faster than HDDs.
Related - CA-064
Cloud Storage
IntermediateDefinition. A service that stores data on remote internet servers so it can be accessed from anywhere, such as Google Drive and Microsoft OneDrive.Cloud storage is a form of cloud computing where files are kept online rather than only on a local device. Google Drive offers 15 GB of free space per account and Microsoft OneDrive offers 5 GB free. It provides access from any connected device and easy sharing, though it depends on an internet connection. For exams, remember the free limits and that cloud storage keeps data on remote servers.
Related
Software and Programming
ENTRIES 065 TO 076
- CA-065
Software
BasicDefinition. A collection of programs and instructions that tell the computer hardware what to do, divided into system software and application software.Software is the intangible set of programs, in contrast to hardware, the physical parts. It is grouped into system software, which runs the machine, and application software, which does user tasks. Without software, hardware cannot perform any useful work. For exams, the two broad categories, system and application, are the key classification.
Related - CA-066
System Software
IntermediateDefinition. Software that provides a base platform to run and manage the computer, controlling operations and hardware, such as the operating system and BIOS.System software includes the operating system, BIOS, device drivers, language translators and utility programs. It coordinates all hardware and lets application software run on top of it. Language translators such as assemblers, compilers and interpreters are part of system software. For exams, place the operating system and translators firmly under system software.
Related - CA-067
Application Software
BasicDefinition. Software designed to help the user perform specific tasks, such as writing documents, making spreadsheets or browsing the web.Word processors like MS Word, spreadsheet programs like MS Excel and web browsers like Google Chrome are application software. Each program serves a particular purpose chosen by the user. It runs on top of the system software rather than managing the hardware directly. For exams, remember that application software is task specific and user facing.
Related - CA-068
Utility Software
IntermediateDefinition. System software that enhances the performance of a computer and manages its resources, such as antivirus programs, disk cleanup and compression tools.Utilities perform housekeeping tasks that keep the system healthy, including antivirus, backup, disk defragmenter, firewall and file management tools. They are a subset of system software focused on maintenance rather than user tasks. A disk cleanup tool freeing space is a familiar example. For exams, classify antivirus and defragmenter as utility software.
Related - CA-069
Firmware
IntermediateDefinition. Permanent software embedded in a hardware device's read only memory that provides the basic instructions for how the device operates.Firmware sits between hardware and software, giving a device its low level control instructions, with the BIOS being a classic example. It is stored in ROM or flash memory so it is not lost when power is removed. Devices such as routers, printers and washing machines all run firmware. For exams, remember firmware as permanent instructions embedded in hardware, exemplified by BIOS.
Related - CA-071
Programming Language
BasicDefinition. A set of words, symbols and rules used to write instructions that a computer can execute, letting humans communicate tasks to the machine.Programming languages range from low level machine and assembly languages to high level languages closer to human speech. An algorithm is a step by step method to solve a problem, and a flowchart is its graphical representation. Every program is ultimately translated into machine code for execution. For exams, remember the ladder from machine language up to high level language.
Related - CA-072
Machine Language
AdvancedDefinition. The lowest level language, written in binary form using only 0s and 1s, which the computer can understand and execute directly.Machine language is the only language the CPU understands without translation, so it runs very fast. It is called the first generation language and is machine dependent, meaning code written for one processor may not run on another. It is extremely difficult for humans to read or write and demands deep hardware knowledge. For exams, fix machine language as binary, first generation and directly executed.
Related - CA-073
Assembly Language
AdvancedDefinition. A low level language that replaces binary instructions with short symbolic codes called mnemonics, translated to machine code by an assembler.Mnemonics such as ADD or MOV are easier to remember than binary, making assembly the second generation language. Because the CPU cannot understand mnemonics, an assembler converts assembly code into machine code. It is still machine dependent and requires knowledge of the hardware. For exams, connect assembly language with mnemonics, the assembler and the second generation.
Related - CA-074
High Level Language
IntermediateDefinition. A language close to human language, using English like keywords and grammar rules, that must be translated to machine code by a compiler or interpreter.High level languages such as C, Java, Python and COBOL are easier to learn and are machine independent, so the same program can run on different computers. They use reserved keywords and a defined syntax. Because the CPU cannot understand them directly, a compiler or interpreter translates them to low level code. For exams, remember high level languages as machine independent and human friendly.
Related - CA-075
Compiler and Interpreter
AdvancedDefinition. A compiler translates a whole high level program at once into machine code, while an interpreter translates and executes it line by line.A compiler reads the entire program, generates an intermediate object code, needs more memory, and reports all errors after checking, as in C and C plus plus. An interpreter reads one line at a time, produces no object code, needs less memory, and reports errors line by line, as in Python. This line by line versus whole program contrast is a very common exam question. Both are types of language translators within system software.
Related - CA-076
Assembler, Linker and Loader
AdvancedDefinition. An assembler converts assembly code to machine code, a linker combines object files into one executable, and a loader loads it into memory to run.The assembler translates mnemonic assembly instructions into binary machine code. The linker joins several separately compiled object files, plus library code, into a single executable program. The loader then places that executable into main memory and prepares it for execution. For exams, keep the roles distinct: assemble, then link, then load.
Related
Operating Systems
ENTRIES 077 TO 086
- CA-077
Operating System
BasicDefinition. System software that controls the resources of a computer and acts as an interface between the user and the hardware.The operating system is the most important system software and is often called the resource controller of the machine. It manages the processor, memory, files and devices, letting application software run without dealing with hardware directly. Common examples are Windows, Linux, macOS and Android. For exams, remember it as the interface between the user and the hardware.
Related - CA-078
Functions of Operating System
IntermediateDefinition. The main jobs of an operating system, including process management, memory management, file management, device management and security.An operating system schedules processes for the CPU, allocates and frees memory, organises files, controls input and output devices, and enforces security. It also handles error detection and command interpretation. These functions run in the background so the user experiences a smooth system. For exams, be ready to list process, memory, file and device management along with security.
Related - CA-079
Booting
IntermediateDefinition. The process of starting a computer and loading the operating system into memory when the machine is switched on.When you power on a computer, the BIOS runs a self test and then loads the operating system, which is booting. Starting from a fully off state is called cold booting, while restarting an already running computer is warm booting. The boot sequence is the ordered set of operations that loads the OS. For exams, distinguish cold boot, from switched off, and warm boot, a restart.
Related - CA-080
Windows OS
BasicDefinition. A popular graphical operating system from Microsoft, with Windows 11 as the current version and Windows 11 26H2 arriving in late 2026.Windows stands for Wide Interactive Network Development for Office Work Solution and is the most widely used desktop operating system. The lineup runs from Windows 95 and XP through Windows 7, 8 and 10 up to Windows 11, so exams may still list older versions. The built in browser is now Microsoft Edge, which replaced Internet Explorer. Verify the current version before your exam, since Microsoft ships annual updates.
Related - CA-081
Linux
IntermediateDefinition. An open source operating system developed by Linus Torvalds in 1991, known for being highly secure and freely modifiable.Linux is not owned by a single company and its source code is open, so anyone can study and change it. Popular distributions include Ubuntu, Fedora, Debian, Mint and Red Hat, many of which power servers across India. Its stability and security make it common in banking servers and supercomputers. For exams, connect Linux with Linus Torvalds, 1991 and open source.
Related - CA-082
Unix
AdvancedDefinition. A multitasking, multiuser operating system developed in 1971 at Bell Labs by Ken Thompson and Dennis Ritchie, whose old name was UNICS.Unix supports many users and many tasks at once and heavily influenced later systems, including Linux and macOS. Its full form is Uniplexed Information and Computing System. Variants include HP-UX, IBM AIX, Oracle Solaris and FreeBSD. For exams, tie Unix to Bell Labs, 1971, and the developers Thompson and Ritchie.
Related - CA-083
macOS
IntermediateDefinition. Apple's operating system for Mac computers, with macOS 26 Tahoe as the current version and macOS 27 Golden Gate arriving in September 2026.macOS is a Unix based system whose built in browser is Safari, and it is known for a polished graphical interface. Apple has moved to year based naming, so the version jumped to macOS 26 Tahoe, with macOS 27 Golden Gate following. Earlier releases carried names such as Catalina, Big Sur, Monterey, Ventura, Sonoma and Sequoia. Verify the current version before your exam, as Apple releases a new version each year.
Related - CA-084
Android
BasicDefinition. An open source operating system owned by Google and designed mainly for touch screen mobile devices, first released in 2008.Android powers most smartphones in India and is built on the Linux kernel. Its earlier versions carried dessert names such as KitKat, Lollipop, Oreo and Pie, after which Google switched to numbers, with Android 16 as the current stable release and Android 17 in testing. It supports a vast app ecosystem through the Google Play Store. Verify the latest version before your exam, since Android updates yearly.
Related - CA-085
Batch and Multiprogramming OS
AdvancedDefinition. A batch operating system groups similar jobs and runs them without interaction, while a multiprogramming system keeps several jobs in memory to keep the CPU busy.In batch processing, jobs with similar needs are collected and executed one after another, as in early payroll or banking systems, with no job prioritisation. Multiprogramming loads multiple ready jobs into memory so the CPU is never idle, increasing utilisation. Time sharing, a logical extension, lets many users share the CPU to minimise response time. For exams, contrast batch, one job group at a time, with multiprogramming, many jobs in memory together.
Related - CA-086
Real Time Operating System
AdvancedDefinition. An operating system that processes data within a fixed, strict time limit, used where a timely response is critical.A real time operating system, or RTOS, guarantees a response inside a set deadline, which is vital for control tasks. A soft real time system, such as a digital camera or mobile phone, tolerates small delays, while a hard real time system, such as a car airbag or anti lock brake controller, cannot miss its deadline. Timing, not raw speed, is the defining feature. For exams, split RTOS into soft and hard with the airbag as the classic hard example.
Related
Microsoft Office Suite
ENTRIES 087 TO 098
- CA-087
Microsoft Office
BasicDefinition. A family of productivity applications from Microsoft, available as the subscription based Microsoft 365 with Copilot AI and the standalone Office 2024.First announced by Bill Gates in 1988, Office bundles Word, Excel, PowerPoint, Outlook and more. Today Microsoft promotes the subscription Microsoft 365, formerly Office 365, which adds the Copilot AI assistant, alongside the perpetual Office 2024 for one time buyers. Famous older versions include Office 2007, 2010, 2013, 2016 and 2019. Verify the current version before your exam, as Microsoft updates the suite regularly.
Related - CA-088
Microsoft Word
BasicDefinition. A word processor used to create, edit, format, store and print text documents, saving files with the .doc or .docx extension.Word is the flagship document application, offering formatting, spell check, tables and images. Its ribbon has tabs such as File, Home, Insert, Design, Layout, References, Mailings, Review and View. The File tab opens the backstage view for saving, printing and sharing. For exams, remember the .docx extension and the main ribbon tabs.
Related - CA-089
Word Processing Features
IntermediateDefinition. Common Word tools including mail merge, header and footer, watermark, thesaurus, macros and the four text alignment options.Mail merge produces many personalised letters or labels by combining a Word document with a recipient list, often an Excel workbook, which is very useful for bulk bank notices. Header and footer place repeating information like page numbers at the top and bottom. A watermark is a faded background image, and the thesaurus finds synonyms. For exams, know mail merge, watermark and the alignments left, right, centre and justify.
Related - CA-090
Microsoft Excel
BasicDefinition. A spreadsheet application used for calculation, charting and data analysis, with files saved in the .xlsx format.Excel arranges data in a grid of rows and columns, supports formulas, pivot tables and a macro language called Visual Basic for Applications. Its ribbon tabs include Home, Insert, Page Layout, Formulas, Data, Review and View. It is widely used in banking for reports and analysis. For exams, remember the .xlsx extension and the spreadsheet grid layout.
Related - CA-091
Cell and Cell Address
IntermediateDefinition. A cell is the intersection of a row and a column in a spreadsheet, and its cell address combines the column letter and the row number, such as B9.The cell currently in use is called the active cell. Columns are labelled with letters and rows with numbers, so the cell where column B meets row 9 has the address B9. In Excel 2007 and later a sheet has 16,384 columns and 1,048,576 rows. For exams, remember the cell address format, column letter followed by row number.
Related - CA-092
Excel Formula and Function
IntermediateDefinition. A formula performs a calculation in a cell, always beginning with an equals sign, and a function is a built in formula such as SUM or AVERAGE.Every formula starts with the equals sign, then a function name and arguments, for example AVERAGE of B1 to B9 finds the mean of that range. Multiple arguments are separated by commas, and a colon marks a range such as A1 to A3. Functions save typing and reduce errors. For exams, remember that formulas begin with the equals sign and that a range uses a colon.
Related - CA-093
Common Excel Functions
AdvancedDefinition. Frequently used Excel functions including SUM, AVERAGE, COUNT, IF, SUMIF, COUNTIF, MAX, MIN, and the text functions LEFT, RIGHT and LEN.SUM adds numbers, AVERAGE finds the mean, and COUNT counts numeric values, while COUNTA counts non blank cells. IF tests a condition and returns one of two results, and SUMIF and COUNTIF add or count only cells meeting a criterion. MAX and MIN return the largest and smallest values. For exams, be able to state what each of these standard functions does, as they appear directly in objective questions.
Related - CA-094
Microsoft PowerPoint
BasicDefinition. A slideshow presentation program used to create slides with text, images, animation and transitions, saved with the .pptx extension.PowerPoint arranges content on slides and lets the user add themes, transitions between slides and animations for objects. Its ribbon includes tabs such as File, Home, Insert, Design, Transitions, Animations, Slide Show, Review and View. The slide sorter and reading views help organise and preview a deck. For exams, remember the .pptx extension and the difference between transitions, which act between slides, and animations, which act on objects.
Related - CA-095
Microsoft Outlook
IntermediateDefinition. The mailing and personal information application in Microsoft Office, used to send and receive email and manage calendars and contacts.Outlook is the primary email client bundled with Office and is widely used in Indian offices and banks for professional communication. It also manages calendars, tasks, notes and contacts in one place. Microsoft is moving users to a redesigned New Outlook, so exams may reference both classic and new versions. For exams, remember Outlook as the mailing software within the Office suite.
Related - CA-096
Workbook and Worksheet
IntermediateDefinition. A worksheet is a single grid of rows and columns, and a workbook is an Excel file that contains one or more worksheets.When you open Excel you work in a worksheet, and the file that holds several sheets together is the workbook. The sheet tab at the bottom shows and switches between worksheets. A shortcut to insert a new worksheet is Shift plus F11. For exams, keep the relationship clear: many worksheets make up one workbook.
Related - CA-097
File Extensions
IntermediateDefinition. A file extension is the suffix after the dot in a filename that indicates the file type, such as .docx for Word or .xlsx for Excel.Extensions tell the operating system which program should open a file. Common Office extensions are .docx for Word, .xlsx for Excel, .pptx for PowerPoint and .accdb for Access. Other frequently tested ones include .pdf, .jpeg, .png, .mp3, .mp4 and .exe for an executable. For exams, memorise the extensions of the main Office applications and popular media formats.
Related - CA-098
Common Shortcut Keys
BasicDefinition. Keyboard combinations that speed up work, such as Ctrl plus C to copy, Ctrl plus V to paste, Ctrl plus Z to undo and Ctrl plus S to save.Shortcuts work across Office applications, for example Ctrl plus B for bold, Ctrl plus X to cut and Ctrl plus A to select all. In Excel, Ctrl plus semicolon inserts the current date and F2 edits the active cell. In PowerPoint, F5 starts the slideshow. For exams, memorise the common Ctrl based shortcuts as they are direct one-mark questions.
Related
Computer Networks and Internet
ENTRIES 099 TO 118
- CA-099
Computer Network
BasicDefinition. A collection of two or more computers and devices linked together to exchange information, data and resources.Networks let devices share files, printers and an internet connection, and they are classified by size into LAN, MAN and WAN. The main networks in India range from a home LAN to the internet, which is a global WAN. Networking enables email, web browsing and online banking. For exams, define a network as linked devices sharing resources.
Related - CA-100
Data Communication
AdvancedDefinition. The exchange of data between two or more devices through a transmission medium, judged by delivery, accuracy, timeliness and low jitter.A data communication system depends on the sender, receiver, message, transmission medium and protocol. Its effectiveness rests on delivering data to the right place, accurately, on time, and with little jitter, the variation in packet arrival time. These five components appear frequently in exams. For exams, list the five components and the four characteristics of good data communication.
Related - CA-101
LAN, MAN and WAN
BasicDefinition. Networks classified by area: LAN covers a small area, MAN spans a city, and WAN covers a large region such as a country or the world.A local area network, LAN, connects devices within a building such as an office or school. A metropolitan area network, MAN, covers a city, with cable television as a common example. A wide area network, WAN, spans large distances, and the internet is the largest WAN. For exams, order them by increasing size, LAN then MAN then WAN.
Related - CA-102
PAN, CAN and SAN
IntermediateDefinition. A PAN links a single user's personal devices, a CAN connects several LANs on a campus, and a SAN is a high speed network for block level storage.A personal area network, PAN, works over a few metres, connecting a phone, laptop and earphones through USB, Bluetooth or NFC. A campus area network, CAN, links the LANs of a university or corporate campus. A storage area network, SAN, provides fast, block level access to shared storage. For exams, match each to its scope: personal, campus and storage.
Related - CA-103
VPN
AdvancedDefinition. A virtual private network extends a private network across a public network like the internet, letting users send data securely as if directly connected.A VPN creates an encrypted tunnel over the public internet so remote users can safely access a private network, which many companies and banks use for secure work from home. It protects data from interception and hides the user's location. It combines convenience with security. For exams, define a VPN as a secure private connection running over a public network.
Related - CA-104
Network Topology
IntermediateDefinition. The physical or logical arrangement of devices in a network, with the main types being bus, ring, star, mesh and tree.In a bus topology all devices share one central cable, while in a ring they connect in a circle. A star topology links every device to a central hub or switch and is the most common today, though the whole network fails if the central device fails. A mesh connects every node to every other node for high reliability, and a tree combines bus and star. For exams, know the shape and one strength or weakness of each topology.
Related - CA-105
Transmission Media
AdvancedDefinition. The path that carries data from source to destination, divided into guided media such as cables and unguided wireless media.Guided media include twisted pair cable, coaxial cable and fibre optic cable, which sends data as pulses of light and offers the highest bandwidth. Unguided media are wireless and include radio waves, microwaves and infrared, each with a different frequency range. Fibre optics is fastest, while infrared, as in a TV remote, works only over short line of sight. For exams, split media into guided cables and unguided wireless.
Related - CA-106
Transmission Modes
IntermediateDefinition. The direction of data flow between devices: simplex is one way, half duplex is two way but not at once, and full duplex is two way at the same time.In simplex mode data flows in only one direction, as from a keyboard to a computer. In half duplex both sides can send and receive but not simultaneously, like a walkie talkie. In full duplex both send and receive at the same time, as in a telephone call. For exams, match each mode to its classic example.
Related - CA-107
OSI Model
AdvancedDefinition. The Open Systems Interconnection model, approved by ISO in 1984, is a seven layer framework describing how data moves from sender to receiver.The seven layers, from bottom to top, are Physical, Data Link, Network, Transport, Session, Presentation and Application. The Network layer handles logical IP addressing and routing, while the Data Link layer handles physical MAC addressing. The OSI model is a reference model, not a protocol. For exams, memorise the seven layers in order and the key job of the Network and Data Link layers.
Related - CA-108
TCP/IP Model
AdvancedDefinition. The practical networking model that runs the internet, using the Transmission Control Protocol and Internet Protocol to move data as packets.TCP/IP is a compact model, often shown in four layers, that maps onto the seven layer OSI model. TCP ensures reliable, ordered delivery of data, while IP handles addressing and routing across networks. It is the standard protocol suite that links billions of devices worldwide. For exams, remember TCP for reliable delivery and IP for addressing and routing.
Related - CA-109
IP Address
AdvancedDefinition. A unique logical address that identifies a device on a network, existing as 32 bit IPv4 and 128 bit IPv6 versions.IPv4 uses four numbers separated by dots, such as 192.168.100.10, giving about four billion addresses, while IPv6 uses a longer 128 bit format to allow vastly more. IP addresses are grouped into classes A to E, and a static IP is fixed while a dynamic IP is assigned by a DHCP server. The loopback address range starting at 127.0.0.1 tests the local machine. For exams, remember IPv4 as 32 bit and IPv6 as 128 bit.
Related - CA-110
MAC Address
AdvancedDefinition. The Media Access Control address is a unique 48 bit physical address burnt into a device's network card, written in hexadecimal.Unlike the IP address, which is logical and can change, the MAC address is a permanent hardware identity assigned by the manufacturer. It is 48 bits or 6 bytes, shown as six hexadecimal pairs, and works at the Data Link layer of the OSI model. It uniquely identifies a network interface within a local network. For exams, contrast the MAC address, physical and fixed, with the IP address, logical and changeable.
Related - CA-111
Router
IntermediateDefinition. A network device that works at the Network layer, forwarding data packets between networks by choosing the best available path.A router connects different networks, such as a home network to the internet, and directs traffic efficiently to reduce congestion. Its main functions are addressing and routing, acting as a traffic controller. It works at the Network layer of the OSI model. For exams, remember the router as the Network layer device that finds the best path between networks.
Related - CA-112
Switch and Hub
AdvancedDefinition. A hub broadcasts data to all connected devices at the Physical layer, while a switch intelligently sends data only to the intended device at the Data Link layer.A hub is a simple connector that copies incoming data to every port with no filtering, so it is inefficient. A switch works at the Data Link layer, filters data and forwards it only to the correct device, so it is called an intelligent hub. This filtering reduces network traffic. For exams, contrast the hub, broadcast and Physical layer, with the switch, targeted and Data Link layer.
Related - CA-113
Modem
IntermediateDefinition. A device that works at the Physical layer to modulate digital signals to analog and demodulate analog back to digital for communication over lines.The name modem comes from modulator and demodulator, its two functions. Modulation converts digital data to analog for transmission, and demodulation converts it back to digital at the other end. It lets computers communicate over telephone or cable lines. For exams, remember modem as modulator plus demodulator working at the Physical layer.
Related - CA-114
Bridge, Gateway and Repeater
AdvancedDefinition. A bridge connects similar networks at the Data Link layer, a gateway connects networks with different protocols across all layers, and a repeater boosts weak signals.A bridge joins two similar networks and can split a large network into smaller segments at the Data Link layer. A gateway is a combination of hardware and software that connects networks using different protocols and works across all layers of the OSI model. A repeater regenerates and strengthens weak signals at the Physical layer so they travel farther. For exams, match each device to its layer and role.
Related - CA-115
Internet
BasicDefinition. A global system of interconnected computer networks using the TCP/IP protocol suite to link billions of devices worldwide.The internet is a network of networks joining private, public, academic and government systems across the world. It grew from ARPANET in 1969 and was launched in India by VSNL in 1995. It supports services such as email, the World Wide Web and online banking. For exams, describe the internet as a global network of networks running on TCP/IP.
Related - CA-116
World Wide Web
BasicDefinition. A system of interlinked hypertext documents and files accessed over the internet through web browsers, created by Tim Berners-Lee in 1989.The web is a service that runs on top of the internet, letting users view web pages linked by hyperlinks. It was invented by Tim Berners-Lee, a British scientist, and the first graphical browser was Mosaic in 1993. People often confuse the web with the internet, but the internet is the underlying network and the web is a service on it. For exams, credit the web to Tim Berners-Lee and separate it from the internet itself.
Related - CA-117
URL and Domain Name
IntermediateDefinition. A URL is the full web address of a resource, while a domain name is the readable part that identifies the server hosting a website.URL stands for Uniform Resource Locator and includes the protocol, domain and path, for example the address of a page on a site. The domain name, such as affairstap.com, maps to a server's IP address so people need not remember numbers. Common top level domains include .com, .org, .edu, .gov and the Indian .in and .co.in. For exams, remember URL as the full address and the domain name as its readable server portion.
Related - CA-118
Cloud Computing
AdvancedDefinition. The delivery of shared computing resources, such as storage and processing, over the internet on demand rather than from a local computer.Cloud computing lets users access servers, storage and software online, paying only for what they use. Public clouds serve many customers, a private cloud serves one organisation, and a hybrid cloud combines both. Google Drive and Microsoft OneDrive are familiar consumer examples of cloud services. For exams, know the public, private and hybrid cloud types and the on demand nature of the service.
Related
Database Management System
ENTRIES 119 TO 128
- CA-119
Database
BasicDefinition. An organised collection of interrelated data, usually stored in the form of tables, so it can be easily accessed and managed.A database keeps related information together, for example a bank storing customer names, account numbers and balances in linked tables. Storing data this way avoids the repetition and confusion of scattered files. It forms the foundation on which a database management system operates. For exams, define a database as an organised collection of interrelated data in tables.
Related - CA-120
Database Management System (DBMS)
BasicDefinition. Software that lets users create, store, retrieve and manage a database, acting as a bridge between the user and the stored data.A DBMS solves the problems of the older file oriented approach, such as data redundancy, inconsistency and difficulty in accessing data. Examples include Oracle, MySQL, MS SQL Server and MS Access, several of which run India's banking systems. It handles storage, security and concurrent access to data. For exams, remember a DBMS as software to create and maintain a database.
Related - CA-121
RDBMS
AdvancedDefinition. A Relational Database Management System stores data in related tables of rows and columns, where each row is a record and each column an attribute.The relational model, based on Edgar Codd's ideas, organises data into tables that can be linked through keys. Popular RDBMS software includes Oracle, MySQL and MS SQL Server. It reduces redundancy and enforces relationships between tables. For exams, remember that an RDBMS uses interrelated tables and is queried using SQL.
Related - CA-122
Table, Tuple and Attribute
IntermediateDefinition. In a relational database a table stores data in rows and columns, a tuple is a single row or record, and an attribute is a column or field.A table is a grid where each row, called a tuple, holds one record and each column, called an attribute, defines a property. For example, in a customer table one row is a single customer and the columns are name, account number and balance. The relation schema names the table with its attributes. For exams, fix tuple as a row and attribute as a column.
Related - CA-123
Primary Key
IntermediateDefinition. A column or set of columns that uniquely identifies each record in a table, and which must be unique and never null.The primary key ensures no two rows are identical, for example an account number in a bank table. Its two rules are that it must be unique and not null. It is the main way to reference a specific record. For exams, remember the primary key rule: unique plus not null.
Related - CA-124
Foreign Key
AdvancedDefinition. A column in one table that refers to the primary key of another table, creating a link between the two tables.When a master table shares its primary key with another table, that shared column in the second table is the foreign key, also called a reference key. It enforces referential integrity, ensuring related records match across tables. For example, an account number used in a transactions table links back to the customer table. For exams, define a foreign key as another table's primary key used to link tables.
Related - CA-125
Degree and Cardinality
AdvancedDefinition. In a relational table, degree is the total number of attributes or columns, while cardinality is the total number of tuples or rows.If a customer table has five columns, its degree is five, and if it holds two hundred rows, its cardinality is two hundred. These two measures describe the width and height of a table. Attribute domain refers to the allowed values of an attribute. For exams, keep the pair straight: degree counts columns, cardinality counts rows.
Related - CA-126
DBMS Architecture
AdvancedDefinition. The generalised three level ANSI/SPARC architecture of a DBMS, made of the external, conceptual and internal levels of data abstraction.The external or view level is the highest and shows each user only the part of the database they need. The conceptual or logical level describes the whole database and the relationships within it. The internal or physical level is the lowest and describes how data is actually stored. For exams, order the three levels from external at the top to internal at the bottom.
Related - CA-127
SQL
IntermediateDefinition. Structured Query Language, a special purpose language designed to create and manage relational databases, developed at IBM in the 1970s.SQL lets users define tables, insert and update data, and run queries to retrieve information. It was first developed by IBM researchers Raymond Boyce and Donald Chamberlin. It is the standard language across relational database systems such as Oracle and MySQL. For exams, remember SQL as the language to create and manage an RDBMS.
Related - CA-128
DDL, DML, DCL and TCL
AdvancedDefinition. The four sublanguages of SQL: DDL defines structure, DML manipulates data, DCL controls access, and TCL manages transactions.Data Definition Language uses commands such as Create, Alter and Drop to define the database structure. Data Manipulation Language uses Select, Insert, Update and Delete to work with data. Data Control Language uses Grant and Revoke for permissions, and Transaction Control Language uses Commit, Rollback and Savepoint. For exams, match each sublanguage to its typical commands.
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Computer Security and Malware
ENTRIES 129 TO 140
- CA-129
Malware
BasicDefinition. Short for malicious software, any program written to enter a computer without permission and damage, disrupt or steal from the system.Malware is an umbrella term covering viruses, worms, trojans, spyware, adware, ransomware, rootkits and keyloggers. It reaches a system through infected files, downloads, email attachments or removable media. Antivirus software is the main defence against it. For exams, treat malware as the broad category and know the specific types listed under it.
Related - CA-130
Computer Virus
BasicDefinition. A malicious program that attaches its code to other executable files and spreads when an infected file is run by the user.The name virus is sometimes expanded as Vital Information Resource Under Siege. A virus stays inactive until the infected host file is opened, then it copies itself and damages data. Types include boot sector virus, macro virus, file virus and stealth virus. For exams, remember that a virus needs a host file and human action to spread, unlike a worm.
Related - CA-131
Worm
IntermediateDefinition. A self replicating malicious program that spreads across a network on its own, without needing a host file or human action.A worm, sometimes expanded as Write Once Read Many in a different context, copies itself using network connections to reach other computers. Unlike a virus, it does not require a host program or user interaction, so it spreads faster. It can consume bandwidth and slow entire networks. For exams, the key contrast is that a worm spreads by itself while a virus needs a host and a user.
Related - CA-132
Trojan Horse
IntermediateDefinition. A malicious program disguised as a useful application that tricks the user into running it, then performs harmful actions in the background.Like the wooden horse of legend, a trojan looks like a genuine, helpful program but hides a harmful payload. By definition it does not self replicate, which separates it from viruses and worms. It is often used to create a backdoor for attackers. For exams, remember the trojan as disguised malware that does not self replicate.
Related - CA-133
Ransomware
IntermediateDefinition. Malicious software that blocks access to a computer or encrypts its files and demands a ransom payment to restore access.Ransomware locks the victim out of their data and displays a demand for money, often in cryptocurrency. Major global attacks such as WannaCry showed how damaging it can be to banks, hospitals and businesses. Regular backups and updated security are the main protections. For exams, define ransomware as malware that demands payment to unlock access.
Related - CA-134
Spyware and Adware
IntermediateDefinition. Spyware secretly collects a user's personal information or browsing activity, while adware displays unwanted advertisements within software.Spyware installs quietly and monitors what the user types or visits, then sends that data to an attacker. Adware embeds advertisements in a program and is sometimes offered as a legal alternative to paying for software. Both invade privacy and can slow the system. For exams, contrast spyware, which spies on the user, with adware, which pushes advertisements.
Related - CA-135
Rootkit and Keylogger
AdvancedDefinition. A rootkit hides the presence of malware deep in the operating system, while a keylogger secretly records every keystroke the user types.A rootkit uses low level operating system tricks to conceal itself and other malware, making it very hard for antivirus software to detect. A keylogger is surveillance software that captures keystrokes, so it can steal passwords, emails and bank details. Both operate silently to avoid the user's notice. For exams, match rootkit with hiding and keylogger with recording keystrokes.
Related - CA-136
Phishing
IntermediateDefinition. A fraud technique that tricks people into revealing sensitive information such as passwords or card details by pretending to be a trustworthy entity.Phishing usually arrives as a fake email, message or website that imitates a bank or well known service to steal login or card details. It is one of the most common cyber threats faced by Indian bank customers, often through fake SMS or links. Users are advised never to share OTPs or click suspicious links. For exams, define phishing as impersonation to steal sensitive data.
Related - CA-137
Firewall
BasicDefinition. A security system of hardware or software that monitors and controls network traffic to prevent unauthorised access to or from a private network.A firewall acts as a barrier between a trusted internal network and untrusted external networks such as the internet. It allows safe traffic and blocks harmful connections based on set rules. It is a basic protection for computers connected to a LAN or the internet. For exams, remember the firewall as a barrier that blocks unauthorised network access.
Related - CA-138
Encryption
AdvancedDefinition. The process of encoding a message so that only authorised users with the correct key can read it, keeping data safe from attackers.Encryption scrambles readable data into an unreadable form, and only someone with the right key can decrypt it back. It protects online banking, passwords and messaging apps from interception. HTTPS websites and VPNs rely on encryption to secure data in transit. For exams, define encryption as encoding data so only authorised users can read it.
Related - CA-139
Authentication and Authorization
AdvancedDefinition. Authentication verifies a user's identity, such as by a password, while authorization checks what actions or resources that verified user is allowed.Authentication answers who you are, for example checking a user id and password or a fingerprint. Authorization answers what you may do, deciding which files or functions the verified user can access. The two steps work together but are distinct. For exams, keep them separate: authentication proves identity, authorization grants permissions.
Related - CA-140
Bot, Zombie and Botnet
AdvancedDefinition. A bot is a program controlled remotely by an attacker, an infected computer is called a zombie, and many zombies together form a botnet.Once malware turns a computer into a bot, that machine becomes a zombie under the attacker's control. Attackers infect thousands of computers and unite them into a botnet to carry out coordinated attacks, such as flooding a website. Botnets are behind many large scale cyber attacks. For exams, follow the chain: bot infects, computer becomes a zombie, and many zombies form a botnet.
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Artificial Intelligence, ML and Generative AI
ENTRIES 141 TO 150
- CA-141
Artificial Intelligence
BasicDefinition. The branch of computer science that builds machines able to perform tasks needing human intelligence, such as learning, reasoning and problem solving.AI defines fifth generation computing and now appears across banking, healthcare and daily apps in India, from chatbots to fraud detection. It includes narrow AI, which does one specific task well, and the still theoretical general AI, which would match human ability across tasks. Machine learning and deep learning are important subfields of AI. For exams, define AI as machines performing tasks that normally require human intelligence.
Related - CA-142
Machine Learning
AdvancedDefinition. A subfield of artificial intelligence in which computers learn patterns from data and improve at a task without being explicitly programmed for it.Instead of following fixed rules, a machine learning model is trained on examples and then makes predictions on new data. Banks use it for credit scoring, fraud detection and customer churn prediction. Common types are supervised, unsupervised and reinforcement learning. For exams, remember machine learning as systems that learn from data rather than from explicit rules.
Related - CA-143
Deep Learning and Neural Networks
AdvancedDefinition. Deep learning is a form of machine learning that uses artificial neural networks with many layers to learn complex patterns from large data.An artificial neural network is loosely inspired by the human brain, made of connected nodes arranged in layers that pass signals forward. Deep learning stacks many such layers, which lets it handle images, speech and language very well. Training these models needs large datasets and powerful GPUs. For exams, connect deep learning with multi layer neural networks and heavy GPU based training.
Related - CA-144
Natural Language Processing
IntermediateDefinition. NLP is a field of artificial intelligence that lets computers understand, interpret and generate human language in text or speech form.NLP powers virtual assistants, language translation, spam filters and chatbots that customers speak or type to. It combines linguistics with machine learning to make sense of everyday language. Voice assistants and bank helpdesk bots rely heavily on it. For exams, define NLP as the AI field that handles human language.
Related - CA-145
Generative AI
IntermediateDefinition. A type of artificial intelligence that creates new content such as text, images, audio, video or code by learning patterns from large datasets.Generative AI does not just analyse data, it produces original outputs, using neural networks trained on huge collections of examples. It became widely known after ChatGPT launched in November 2022 and is now used for writing, coding and design. It is built on advances in natural language processing, machine learning and deep learning. For exams, define generative AI as AI that generates new content rather than only classifying existing data.
Related - CA-146
Large Language Model
AdvancedDefinition. A large language model, or LLM, is an AI model trained on vast amounts of text to understand and generate human like language.LLMs are the engines behind popular chatbots and are built on the transformer architecture, which lets them handle long passages of text. They are trained on huge text datasets and can answer questions, summarise and write. Examples of model families include OpenAI's GPT series, Google Gemini, Anthropic Claude and Meta Llama. For exams, remember an LLM as a text trained AI model behind modern chatbots, and verify current model names before your exam.
Related - CA-147
AI Chatbots
IntermediateDefinition. Software applications that use large language models to hold natural conversations with users, answering questions and helping with tasks.Popular AI chatbots include ChatGPT from OpenAI, Gemini from Google, Copilot from Microsoft and Claude from Anthropic. They are widely used for writing, learning, coding help and customer support, including in Indian banks. They rely on large language models and natural language processing to respond. For exams, know the major chatbots and that they run on large language models, and verify current versions before your exam.
Related - CA-148
Prompt and Prompt Engineering
IntermediateDefinition. A prompt is the instruction a user gives to an AI model, and prompt engineering is the skill of writing clear prompts to get the best output.The quality of a chatbot's answer depends heavily on how well the prompt is written, so a clear, detailed prompt yields a better result. Prompt engineering is now a recognised skill, involving specific instructions, examples and step by step guidance. It has become important as generative AI enters offices and study. For exams, define a prompt as the user's instruction and prompt engineering as the craft of writing effective prompts.
Related - CA-149
Computer Vision
AdvancedDefinition. A field of artificial intelligence that enables computers to interpret and understand visual information from images and videos.Computer vision lets machines recognise faces, read documents, detect objects and analyse scenes. In India it supports facial recognition in KYC, automatic number plate reading and cheque image processing in banks. It usually relies on deep learning and neural networks trained on large image datasets. For exams, define computer vision as the AI field that makes sense of images and video.
Related - CA-150
AI in Banking
IntermediateDefinition. The use of artificial intelligence in the financial sector for tasks such as fraud detection, chatbots, credit scoring and customer service.Indian banks and regulators increasingly apply AI to spot fraudulent transactions in real time, answer customer queries through chatbots, and assess loan risk. Machine learning models flag unusual patterns, while natural language processing powers virtual assistants. The Reserve Bank of India has also examined AI and its risks in finance. For exams, connect AI in banking with fraud detection, chatbots and credit scoring as common applications.
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