💻 Science & Technology — Computer and Information Technology
1. Introduction to Computer
HISTORY
- Abacus: Earliest known computational tool (China)
- Pascaline: First mechanical calculator by Blaise Pascal
- Father of Computer: Charles Babbage — Difference Engine (1822), Analytical Engine (1837)
- Father of Modern Computer: Alan Turing
CHARACTERISTICS
- Speed: Processes in micro/nano/picoseconds
- Storage: Retains digital data
- Accuracy: Error-free (human errors excepted)
- Versatility: Multi-tasking
- Automation: Self-executes tasks
LIMITATIONS
- No Self Intelligence: Programmed by humans
- Decision Making: Dependent on instructions
- Self Care: Cannot take care of itself
- Memory Retrieval: Linear, unlike human mind
- No Sensation: Cannot feel
2. Generations of Computer
GENERATION COMPARISON
| Generation | Technology | Speed | Language | Examples |
|---|---|---|---|---|
| 1st (1940-56) | Vacuum Tubes | Milliseconds | Machine language | UNIVAC-1, IBM-701 |
| 2nd (1956-63) | Transistors | Microseconds | Assembly, High-level | UNIVAC-1004, IBM-1401 |
| 3rd (1964-71) | Integrated Circuits | Nanoseconds | FORTRAN, COBOL, BASIC | IBM-360, PDP-8 |
| 4th (1971-89) | Microprocessors | Picoseconds | Java, C++, Python | ALTAIL-8800, IBM-370 |
| 5th (1989-) | Artificial Intelligence | — | — | — |
3. Classification of Computers
BASED ON SIZE
- Nano Computer: Microscopic dimensions
- Micro Computer (PC): Desktop, Laptop, Netbook, Tablet, Palmtop/PDA, iPad, iPod, Simputer
- Mini Computer: Smaller than mainframes
- Mainframe Computer: Bulk data processing (census, statistics)
- Super Computer: Massive calculations (weather, engineering, defence)
TOP 10 SUPER COMPUTERS
| Rank | Name | Speed | Country |
|---|---|---|---|
| 1 | Fugaku-Fujitsu | 220 PFLOPS | Japan |
| 2 | Summit-IBM | 148.6 PFLOPS | US |
| 3 | Sierra-IBM | 94.64 PFLOPS | US |
| 4 | Sunway TaihuLight | 93 PFLOPS | China |
| 5 | Tianhe-2A | 61.44 PFLOPS | China |
PRATYUSH — INDIA'S FASTEST SUPERCOMPUTER
- Unveiled at Pune-based IITM (Indian Institute of Tropical Meteorology)
- 6.8 PF computational power
- 4.0 PF at IITM, Pune; 2.8 PF at NCMRW, Noida
- Fourth fastest supercomputer in the world for weather and climate research
BASED ON WORK
- Digital Computer: Operates on binary data (0 and 1)
- Analog Computer: Uses continuous variables (mechanical/hydraulic/electrical)
- Hybrid Computer: Accepts analog signals, processes as digital
OTHER TYPES
- Optical/Photonic Computer: Uses photons instead of electric current
- Virtual Computer: Allows multiple OS to run simultaneously
- Chemical Computer: Based on chemical soup
- DNA Computer: Uses DNA, biochemistry
- Neuro Computer: Built from living neurons
- Quantum Computer: Uses quantum mechanical phenomena
4. Hardware
INPUT DEVICES
- Keyboard, Mouse, Touch Screen, Trackball, Joystick
- MICR: Magnetic Ink Character Recognition
- OMR: Optical Mark Recognition
- OCR: Optical Character Recognition
- Bar Code Reader: Reads bars of varying thickness
- Speech Input Unit: Converts spoken words
OUTPUT DEVICES
- VDU (Monitor): Visual Display Unit
- Printers: Produces text/graphics on paper
- Plotters: Line drawings (engineering applications)
- Graphic Display Device: Displays graphs/pictorial data
- Speech Output Unit: Converts text to spoken sentences
5. Memory
PRIMARY MEMORY
- ROM (Read Only Memory): Non-volatile, resident memory
- PROM: Programmable ROM (not alterable)
- EPROM: Erasable by UV light
- EEPROM: Electrically Erasable
- RAM (Random Access Memory): Volatile, temporary
- SRAM: Static RAM (no refresh needed)
- DRAM: Dynamic RAM (needs periodic refresh)
CACHE MEMORY
- Faster than regular RAM
- Integrated directly with CPU chip
SECONDARY MEMORY
- Magnetic Storage: HDD, Micro SD, Floppy Disk
- Optical Storage: CD, DVD, Blu-ray, Holographic Versatile Disc
- USB Flash Drive: Flash memory with USB interface
- Tertiary Storage: Robotic mechanism for mass storage media
6. Software
SYSTEM SOFTWARE
- Operating System: Manages memory, processes, software/hardware
- Types: DOS (single user), Unix/Linux (multi-user), Mac OS, Windows
- Language Translators: Assembler, Compiler, Interpreter
- MANTRA: Machine Assisted Translation tool (English → Hindi)
UTILITY & APPLICATION SOFTWARE
- Utility: Antivirus, Disk tools, Backup software
- Application: User-defined specific tasks
7. Computer Networks
TYPES OF NETWORKS
- LAN: Local Area Network (≤1 km)
- MAN: Metropolitan Area Network (5-15 km)
- WAN: Wide Area Network (national/global)
- PAN: Personal Area Network (≤10 m)
- WPAN: Wireless PAN (Bluetooth, ZigBee)
- BAN: Body Area Network (wearable devices)
- VPN: Virtual Private Network
8. Cyber Crimes and Security
CYBER CRIMES
- Computer as target: Hacking, virus/worm attacks, DoS attack
- Computer as weapon: Cyber terrorism, credit card frauds, pornography
COMPUTER VIRUSES
- Malware: Malicious software
- Stuxnet: Microsoft Windows worm (2010)
- Ransomware: Threatens to publish/block data unless ransom paid
- Firewall: Controls incoming/outgoing network traffic
SECURITY MANAGEMENT
- Facial Recognition: Identifies from digital image
- Biometric Passport (e-passport): Contains biometric information
- Iris Recognition: Uses mathematical pattern-recognition
- Smart Card: Pocket-sized card with embedded IC
9. Internet
INTERNET IN INDIA
- Launched by VSNL on 15th August, 1995
- Broadband Policy (2004): Defined as ≥256 kbit/s download
DIGITAL INDIA
- Launched: 1st July, 2015
- Vision: Infrastructure + Governance + Digital empowerment of citizens
- Mission: "Power to Empower"
PROTOCOLS
- TCP/IP: Basic communication language
- HTTP: World Wide Web protocol
- FTP: File Transfer Protocol
- Telnet: Remote computer connection
- Gopher: Distributed document retrieval
INTERNET CONNECTION
- Broadband: ≥256 Kbps
- Wi-Fi: Wireless Fidelity (radio waves)
- WiMax: 30-40 Mbps up to 1 Gbps; 4G technology
- LiFi: Light-based communication; 10,000x capacity of radio spectrum
CLOUD COMPUTING
- Storing and accessing data over internet
- Service models: IaaS, PaaS, SaaS
10. Important Services and Terms
SEARCH ENGINES
- Google: Most used search engine
- YouTube: Video sharing (Google)
- Other: Lycos, Altavista, Hot Bot, Bing
INFORMATION TECHNOLOGY IN INDIA
- NIC: National Informatics Centre
- BTISNET: Bio-Technology Information System Network
- NICNET: NIC Network (satellite-based)
- NIXI: National Internet Exchange of India
- STPI: Software Technology Parks of India (1991)
- NeGP: National e-Governance Plan
- Digital Signature: Electronic signing of documents
EMERGING TECHNOLOGIES
- Augmented Reality (AR): Improves real-world experience with computer-generated input
- Virtual Reality (VR): Complete immersion in simulated environment
- Internet of Things (IoT): Physical objects connected to internet
- Robotics: Design, construction, and application of robots
INFORMATION TECHNOLOGY ACT, 2000
- Legal recognition of electronic documents
- Legal recognition of digital signatures
- Offenses and contravention
- Justice Dispensation for cyber crimes
- Amended in 2008
NATIONAL CYBER SECURITY POLICY, 2013
- Protects public and private infrastructure from cyber attacks
- Safeguards personal, finance, and sovereign data
Summary: Computer and IT at a Glance
| Topic | Key Point |
|---|---|
| Father of Computer | Charles Babbage |
| Father of Modern Computer | Alan Turing |
| 1st Generation | Vacuum Tubes |
| 5th Generation | Artificial Intelligence |
| Pratyush | India's fastest supercomputer (6.8 PF) |
| Digital India | Launched 1st July, 2015 |
| IT Act | 2000 (Amended 2008) |
KEY TAKEAWAYS FOR UPSC
- Father of Computer: Charles Babbage (1822 — Difference Engine)
- Generations: 1st (Vacuum Tubes) → 5th (AI)
- Pratyush: India's fastest supercomputer (6.8 PF) at IITM Pune
- Memory: ROM (non-volatile) vs RAM (volatile)
- Digital India: Launched 1st July 2015; "Power to Empower"
- IT Act 2000: Legal recognition of e-documents and digital signatures
- Cyber Security Policy 2013: Protects from cyber attacks
- IoT: Physical objects connected to internet
High-Yield Interactive UPSC Quiz (Science & Technology — Computer and IT)
Q1. Who is known as the Father of Computer?
Correct Answer: B. Charles Babbage is known as the Father of Computer for designing the Difference Engine (1822) and Analytical Engine (1837).
Q2. Which generation of computers used vacuum tubes?
Correct Answer: B. 1st Generation computers (1940-56) used vacuum tubes.
Q3. What is the name of India's fastest supercomputer?
Correct Answer: B. Pratyush is India's fastest supercomputer with 6.8 PF computational power, unveiled at IITM Pune.
Q4. Which type of memory is volatile?
Correct Answer: B. RAM (Random Access Memory) is volatile — its contents are lost when power is switched off.
Q5. When was Digital India launched?
Correct Answer: B. Digital India was launched on 1st July 2015 with the mission "Power to Empower".
Q6. The Information Technology Act was passed in which year?
Correct Answer: B. The Information Technology Act was passed in 2000 and amended in 2008.
Q7. What does IoT stand for?
Correct Answer: A. IoT stands for Internet of Things — a network of physical objects connected to the internet.
Q8. Which protocol is used for file transfer on the internet?
Correct Answer: B. FTP (File Transfer Protocol) is used for transferring files over the internet.
Q9. Which technology uses light waves for data transmission?
Correct Answer: C. LiFi uses visible light spectrum for data transmission, offering 10,000x capacity of radio spectrum.
Q10. The National Cyber Security Policy was framed in which year?
Correct Answer: D. The National Cyber Security Policy was framed in 2013 by the Department of Electronics and Information Technology.