GK · Chapter 16

Computer

Fundamentals · Hardware · Software · Networks · AI · Robotics

Introduction

Father of Computer: Charles Babbage
Father of Modern Computer: Alan Turing
First calculating device: Abacus
First digital computer: ENIAC

Generations of Computers

Generation	Period	Technology
First	1940–56	Vacuum Tube
Second	1956–63	Transistor (Semiconductor)
Third	1964–71	Integrated Circuit (Silicon)
Fourth	1971–Present	Integrated Circuit / Microprocessor
Fifth	Present–Future	Large Scale Integrated Circuit, Artificial Intelligence

⚡ QUICK RECALL The third generation of computers began with the IBM 360 — a key marker question in exams.

Classification of Computers

By Size	By Function
Micro Computer	Analog Computer
Mini Computer	Digital Computer
Mainframe Computer	Hybrid Computer
Super Computer	—

Supercomputers

Rank	Top Indian Supercomputers
1	Airawat (CDAC, Pune)
2	Param Siddhi (CDAC, Pune)
3	Pratyush (IITM, Pune)

Rank	Top World Supercomputers
1	El Capitan — California, USA
2	Frontier — USA
3	Aurora System — USA
4	Eagle — USA

⚡ QUICK RECALL On 26 September 2024, PM Narendra Modi launched three PARAM Rudra supercomputers and inaugurated two HPC systems — ArKa and Arunika — for weather and climate research.

Components of a Computer

Input Unit, Output Unit, Central Processing Unit (CPU), Memory Unit

Input Unit	Output Unit
Keyboard, Mouse, Scanner	Printer, Monitor, Touch Screen
Microphone, OCR	Plotters, Speaker
Trackball, Light Pen, MICR	Projector

CPU is the "Brain of the Computer" — comprises Control Unit (CU), Arithmetic Logic Unit (ALU), and Primary Storage Unit.

Primary & Secondary Storage

Storage Type	Details
RAM	Random Access Memory — Temporary, Volatile, Dynamic/Static memory
ROM	Read Only Memory — Permanent, Non-Volatile; types: PROM, EEPROM, EPROM
Secondary Storage	External/auxiliary/backup memory; stores data permanently

Magnetic Storage: Hard Disk Drive, Floppy Disk, Magnetic Tape
Optical Storage: CD-R, DVD, Blu-ray Disc
Solid State Storage: Pen Drive, Memory Card

Memory Units

Unit	Equivalent
1 Bit	Binary digit (0 or 1)
8 Bits	1 Byte = 2 Nibbles
1024 Bytes	1 Kilobyte (KB)
1024 Kilobytes	1 Megabyte (MB)
1024 Megabytes	1 Gigabyte (GB)
1024 Gigabytes	1 Terabyte (TB)
1024 Terabytes	1 Petabyte (PB)
1024 Petabytes	1 Exabyte (EB)

Important Hardware Facts

Term	Description
Motherboard	Main/base/system/logic board; central PCB connecting all components
DMA	Direct Memory Access; hardware transfers data to/from memory bypassing CPU
Cache Memory	Fast memory between CPU and main memory; improves data retrieval speed
Burning	Writing data to a CD/DVD using a laser
MAR	Memory Address Register; holds address of memory location to be accessed

System Software & Operating Systems

System Software: collection of programs; handles execution of all tasks
Single-user OS: MS-DOS and Windows 9x
Device drivers: group of directions
Booting: starting or restarting a computer
Window Task Manager: utility application of MS Windows
Standby: power management feature of Windows

Types of Operating Systems
Batch Operating System
Time-Sharing Operating System
Distributed Operating System
Network Operating System
Multi-Tasking Operating System
Multi-Processing Operating System

Utility, Application & Open Source Software

Utility Software	Function
Disk Compression	Reduces file/folder size on storage
Disk Cleaners	Deletes temporary/junk files
Disk Defragmenter	Rearranges fragmented files
Text Editor	Creating/editing text files (e.g., Notepad)
Anti-Virus	Avira, Kaspersky, AVG, etc. — removes viruses

Application Software: word processing, presentation, reservation systems, payroll, office management, etc.
Open Source Software: Linux, Firefox, Google Chrome, Opera — source code freely available to anyone
Shortcut for renaming files/folders in Windows: F2
DBMS: manages comprehensive data collection and query execution
Spreadsheet Software: used for financial statements

Programming Languages

Low-Level: Machine Language (0s & 1s), Assembly Language
Medium-Level: bridge between low and high-level languages
High-Level: uses English words and mathematical symbols

Language	Application
FORTRAN	Mathematical applications
ALGOL	Scientific applications
LISP	Artificial intelligence
COBOL	Business applications
BASIC / PASCAL	Teaching programming
C	System programming
C++	System object programming
JAVA	Internet-based programming

Translator	Function
Assembler	Translates assembly code to machine code
Compiler	Translates entire high-level code to machine code before execution
Interpreter	Executes high-level code line by line

Microsoft Office Suite

Application	Key Facts
MS Word	Word processing; File format: .doc/.docx; Default font: Aptos (replaced Calibri in early 2024)
MS Excel	Spreadsheet program; File format: .xls/.xlsx; default column width: 8 characters
MS PowerPoint	Presentation software; File format: .ppt/.pptx
MS Access	DBMS; File format: .accdb (.mdb prior to Access 2007)

Key Shortcut	Function
F1	Open Help window
F5 (Word)	Open Find & Replace window
F5 (PowerPoint)	Start slide show from beginning
Shift+F5	Start slide show from current slide
F12	Open Save As window
Ctrl+M	Insert new slide (PowerPoint)
Ctrl+U	Underline cell content (Excel)
Ctrl+D	Font dialog box (Word) / Fill Down (Excel)
Ctrl+A	Select all items
Ctrl+C / Ctrl+V	Copy / Paste
Ctrl+P	Print document
Ctrl+B	Bold selected text
Ctrl+K	Insert hyperlink
Ctrl+L	Align text left

⚠ EXAM TRAP F5 does DIFFERENT things in Word (opens Find & Replace / Go To) vs PowerPoint (starts slide show) — the same key, different function per application.

Computer Networks

Type	Coverage	Speed	Location
LAN	1 Mile	10 Mbps – 100 Mbps	School, office, campus
MAN	Up to 50 km	100 Mbps – 1 Gbps	City or metropolitan area
WAN	Up to 1000 km	1 Gbps – 100 Gbps	Network of networks

WAN uses High Level Data Link Control (HDLC) protocol.
Network Devices: Repeater, Gateway, Switch, Router, Modem, Hub
VPN: creates secure, encrypted connection between device and internet
Network Topology: Ring, Bus, Tree, Star, Mesh
ISDN: digital/standard telephone service
Cloud Computing: connects millions of mobile and personal computers via network

Internet

Internet: network of networks connecting computers worldwide
Connections: Dial-up; Broadband (cable modem, fiber optic, DSL); Wireless (Wi-Fi, Wi-MAX, satellite)
World Wide Web (WWW): created by Tim Berners-Lee in 1989
Web Page: documents written in HTML
Web Address: URL — indicates internet address of files
Domain Name: identifies a website (e.g., www.example.com)
Search Engines: Google, Yahoo, AltaVista, Lycos

Protocol	Purpose
TCP	Transmission Control Protocol
IP	Internet Protocol
FTP	File Transfer Protocol
HTTP	Hypertext Transfer Protocol
SMTP	Simple Mail Transfer Protocol

Internet Services: Chatting, Video Conferencing, Social Networking, E-commerce, Blogging, E-mail
Gmail: attachments up to 25 MB; sorts emails by date by default; searchable by From, To, Subject, Date

Mobile Communication Generations

Gen	Year/Country	Technology	Key Feature
1G	Japan, 1979	Analog cellular	Analog radio signal
2G	Finland, 1991	Digital networks	Digital radio signal
3G	Japan, 2001	High-speed IP data	High-speed IP data
4G	Norway & Sweden, 2009	Increased mobile broadband	Higher communication speeds
5G	South Korea, 2019	High-frequency speeds	Download speeds up to 20 Gbps

Telecom Regulatory Authority of India: TRAI

Artificial Intelligence

Origin: 1950s; Founder: John McCarthy
Definition: ability of machines to simulate human cognitive functions
Related field: Natural Language Processing (NLP)

AI Tool	Launch Year	Company
DeepSeek (AI Chatbot)	2025	DeepSeek
Qwen 3	2025	Alibaba
Grok 4	2025	xAI
Gemini	2023	Google DeepMind
ChatGPT	2022	OpenAI

Computer Security

Threat	Description
Malware	Malicious software
Viruses	Damage computer software
Worms	Hide in invisible files
Ransomware	Malicious software demanding ransom
Trojan Horse	Non-self-replicating malware
Spyware	Secretly monitors activity
Hacking / Cracking	Unauthorized system access
Phishing	Network security threat via deception
Firewall	Filters network traffic and control

Anti-Virus Software: Norton, McAfee, Kaspersky, Avast, AVG
MPEG: Moving Picture Experts Group — compression format
Hibernate: power management feature
Skype: requires webcam, microphone, speaker
Two-Factor Authentication: verifies identity (e.g., fingerprint scan)

Important Robots

Robot	Key Details
Rex	World's first bionic man
Kirobo	First talking robot in space
Snake Robot	Assists in accidents (DRDO)
FemiSapien	Intelligent robot
Sophia	Communicates with humans (Saudi Arabia)
Daksha / Netra	Defence Forces robots (DRDO)
Vyommitra	Half-humanoid for Gaganyaan Mission, by ISRO
FEDOR	Russian humanoid robot
Zhurong	China's Mars rover, part of Tianwen-1 mission
Mitra	India's first humanoid robot
Pioneer	Assisted in the Chernobyl disaster (NASA)

⚠ EXAM TRAP Tianwen-1 is the MISSION name; Zhurong is the ROVER that landed as part of that mission — don't treat them as the same entity.

Quick Reference Summary

Father of ComputerCharles Babbage

Father of Modern ComputerAlan Turing

First Digital ComputerENIAC

First Calculating DeviceAbacus

Top Indian SupercomputerAirawat (CDAC, Pune)

Top World SupercomputerEl Capitan (California, USA)

RAMTemporary / Volatile memory

ROMPermanent / Non-Volatile memory

CPUBrain of computer; CU, ALU, Primary Storage

WWW CreatorTim Berners-Lee (1989)

1G TechnologyJapan, 1979; Analog

2G TechnologyFinland, 1991; Digital

5G TechnologySouth Korea, 2019; Download 20 Gbps

AI FounderJohn McCarthy; Origin: 1950s

ChatGPTLaunched 2022; OpenAI

DeepSeekLaunched 2025; DeepSeek

MS Word Default FontAptos (replaced Calibri, early 2024)

DBMS File Format.accdb (.mdb prior to Access 2007)

India's First Humanoid RobotMitra

VyommitraHalf-humanoid by ISRO for Gaganyaan Mission

TRAITelecom Regulatory Authority of India

FirewallFilters network traffic and control