Introduction To Computer

A computer is an electronic device that accepts data as input, processes it according to a set of instructions (programs), and produces information as output.

Characteristics of Computer

• Speed: Performs millions of calculations per second.
• Accuracy: Produces error-free results when given correct input.
• Diligence: Works for hours without getting tired.
• Versatility: Can perform multiple different tasks.
• Storage: Large amounts of data can be stored and retrieved quickly.

Types of Computers TypeExampleUse MicrocomputerDesktop, LaptopPersonal use MinicomputerIBM AS/400Departmental use MainframeIBM Z-SeriesLarge organizations SupercomputerPARAM, CRAYScientific research Hardware Components

• Input Devices: Keyboard, Mouse, Scanner, Webcam, Microphone
• CPU: ALU (Arithmetic Logic Unit) + CU (Control Unit) + Registers
• Memory: RAM (volatile), ROM (non-volatile), Cache
• Output Devices: Monitor, Printer, Speaker, Projector
• Storage: Hard Disk, SSD, Pen Drive, CD/DVD

Number Systems

• Binary (Base 2): 0, 1 — used internally by computers
• Decimal (Base 10): 0–9 — used by humans
• Octal (Base 8): 0–7
• Hexadecimal (Base 16): 0–9, A–F

Units: 1 Bit | 8 Bits = 1 Byte | 1024 B = 1 KB | 1024 KB = 1 MB | 1024 MB = 1 GB | 1024 GB = 1 TB

Generations of Computers

1. 1st Gen (1940–56): Vacuum tubes — ENIAC, UNIVAC
2. 2nd Gen (1956–63): Transistors
3. 3rd Gen (1964–71): Integrated Circuits (ICs)
4. 4th Gen (1972–present): Microprocessors — Personal Computers
5. 5th Gen (Future): AI, Machine Learning, Quantum Computing