- Computer awareness is a separate section in bank exams such as IBPS PO Mains, SBI Clerk and RRB, and appears in SSC and state exams too. The questions are short and factual, which makes it one of the easiest sections to score in.
- Almost everything asked falls into a few buckets: history and generations, memory, hardware, software, networking and the internet, security, and MS Office shortcuts.
- For a one-page revision list, see our Computer Awareness Cheat Code.
History and Generations
- Charles Babbage designed the Analytical Engine and is called the father of the computer; Ada Lovelace wrote what is considered the first computer program.
- Alan Turing laid the theoretical foundations of computing and artificial intelligence.
| Generation | Technology | Example / note |
|---|---|---|
| First (1940s–50s) | Vacuum tubes | ENIAC, UNIVAC; machine language |
| Second (1950s–60s) | Transistors | Assembly and early high-level languages (FORTRAN, COBOL) |
| Third (1960s–70s) | Integrated circuits (ICs) | Operating systems, keyboards and monitors |
| Fourth (1971 onwards) | Microprocessors (VLSI) | Intel 4004 (1971); personal computers |
| Fifth (present and future) | Artificial intelligence, parallel processing | Natural-language and learning systems |
Memory Units
1 nibble = 4 bits; 1 byte = 8 bits; 1 KB = 1,024 bytes; then MB, GB, TB, PB, EB, ZB and YB, each 1,024 times the last.
Types of Memory
| Memory | Key points |
|---|---|
| Registers | Inside the CPU — the fastest memory |
| Cache | Small, very fast memory between the CPU and RAM; made of SRAM |
| RAM | Volatile (loses data when power is off). SRAM is faster and costlier; DRAM must be refreshed |
| ROM | Non-volatile; stores firmware such as the BIOS. PROM (write once), EPROM (erased with ultraviolet light), EEPROM (erased electrically — flash memory is a type) |
| Secondary storage | Hard disk, SSD, pen drive, optical discs — CD (~700 MB), DVD (4.7 GB single layer), Blu-ray (25 GB single layer) |
Father of computerCharles Babbage
1 byte8 bits
Volatile memoryRAM
EPROM erased byUV light
HTTPS port443
IPv6 address128 bits
CPU and Devices
- The CPU ("brain" of the computer) has the ALU (arithmetic and logic), the control unit (directs operations) and registers.
- Input devices: keyboard, mouse, scanner, microphone, joystick. Banks use MICR (Magnetic Ink Character Recognition) to read cheques; OMR reads marked answer sheets; OCR converts printed text into editable text.
- Output devices: monitor, printer (impact: dot-matrix; non-impact: inkjet, laser), speaker, plotter. A touchscreen is both input and output.
Software and Languages
- System software runs the computer — operating systems (Windows, Linux, macOS, Android), device drivers and utilities. Application software does user tasks — word processors, browsers, spreadsheets.
- Linux, created by Linus Torvalds (1991), is open-source; Android is built on the Linux kernel.
- Translators: a compiler converts the whole program at once; an interpreter converts and runs line by line; an assembler converts assembly language into machine code.
- Number systems: binary (base 2), octal (8), decimal (10), hexadecimal (16, digits 0–9 and A–F).
Networking
| Topic | Key points |
|---|---|
| Network types | PAN (personal, e.g., Bluetooth) < LAN (building) < MAN (city) < WAN (country or world — the internet is the largest WAN) |
| Topologies | Bus (single cable), star (central hub or switch — most common), ring, mesh (every device linked — most reliable), tree |
| Devices | Hub (broadcasts to all), switch (sends to the right device), router (connects different networks), modem (converts digital and analog signals), gateway |
Internet and Protocols
- ARPANET (1969) was the forerunner of the internet. Tim Berners-Lee invented the World Wide Web at CERN in 1989.
- IP addresses: IPv4 is 32-bit; IPv6 is 128-bit. DNS translates domain names into IP addresses; DHCP assigns IP addresses automatically.
| Protocol | Use | Default port |
|---|---|---|
| HTTP / HTTPS | Web pages (HTTPS is encrypted) | 80 / 443 |
| FTP | File transfer | 21 |
| SMTP | Sending email | 25 |
| POP3 / IMAP | Receiving email | 110 / 143 |
| Telnet / SSH | Remote login (SSH is secure) | 23 / 22 |
Cyber Security
- A virus attaches to a host file and needs a user action to spread; a worm spreads by itself across networks; a Trojan pretends to be useful software; ransomware encrypts data and demands payment; phishing tricks users into revealing details through fake messages or sites.
- A firewall filters network traffic; two-factor authentication adds a second check beyond a password.
- CERT-In (under MeitY) is India's national agency for responding to cyber security incidents. The IT Act, 2000 is the main cyber law; its Section 66A was struck down in Shreya Singhal v. Union of India (2015).
Useful Shortcuts
| Keys | Action | Keys | Action |
|---|---|---|---|
| Ctrl + C / X / V | Copy / cut / paste | Ctrl + Z / Y | Undo / redo |
| Ctrl + S / P | Save / print | Ctrl + A | Select all |
| F2 | Rename a file | F5 | Refresh (or start a slide show in PowerPoint) |
| Alt + F4 | Close the active window | Ctrl + Shift + Esc | Open Task Manager |
| Windows + L | Lock the computer | Windows + D | Show the desktop |
In Excel, every formula begins with =; a cell address such as B3 is column then row, and $B$3 is an absolute reference that does not change when copied.
- Odd-one-out questions: "Which is NOT an input device?", "Which memory is volatile?".
- Protocol ↔ purpose: SMTP sends mail, POP3/IMAP receive it; HTTPS port 443.
- Full forms: MICR, OMR, EPROM, DHCP, URL, HTML — bank exams ask several every year.
Q1. Which of the following memories is volatile?
✅ Answer: (b) RAM
💡 Explanation: RAM loses its contents when the power is switched off.
Q2. Banks use which technology to process cheques?
✅ Answer: (c) MICR
💡 Explanation: Magnetic Ink Character Recognition reads the special characters printed on cheques.
Q3. Which protocol is used to SEND email?
✅ Answer: (a) SMTP
💡 Explanation: SMTP sends mail; POP3 and IMAP are used to receive it.
Q4. An IPv6 address is how many bits long?
✅ Answer: (d) 128
💡 Explanation: IPv4 uses 32 bits and IPv6 uses 128 bits.
Q5. Malware that copies itself across a network without needing a host file is a:
✅ Answer: (b) Worm
💡 Explanation: Worms spread on their own; viruses need a host file and usually a user action.
🔁 Revise in 60 Seconds
- Babbage — father of computer; generations: vacuum tube → transistor → IC → microprocessor → AI.
- 1 byte = 8 bits, 1 KB = 1,024 bytes. RAM volatile; ROM non-volatile; EPROM — UV; registers fastest.
- MICR cheques, OMR answer sheets. Compiler whole program; interpreter line by line.
- HTTP 80, HTTPS 443, FTP 21, SMTP 25 (send), POP3 110 (receive). IPv4 32-bit, IPv6 128-bit. Worm self-spreads.
📌 Prelims Traps to Avoid
- ✘ ROM is non-volatile, but it is still primary memory.
- ✘ A switch sends data only to the intended device; a hub broadcasts to all.
- ✘ Tim Berners-Lee invented the Web, not the internet.
What is the difference between RAM and ROM?
RAM (Random Access Memory) is volatile working memory that loses its data when the power is off and can be read and written freely. ROM (Read Only Memory) is non-volatile and stores permanent instructions such as the BIOS.
Which protocols are used for email?
SMTP (port 25) is used to send email. POP3 (port 110) and IMAP (port 143) are used to receive it — POP3 usually downloads messages to one device, while IMAP keeps them synchronised on the server.