🖥️ What is a Computer?

A computer is an electronic device that processes data according to a set of instructions called a program. It performs input, processing, storage, and output operations to produce useful information.

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🔁 Basic Functions of a Computer

1. Input – Accepts data (e.g., keyboard, mouse).

2. Processing – Handles data using the CPU.

3. Storage – Saves data (temporarily in RAM, permanently in HDD/SSD).

4. Output – Displays results (e.g., monitor, printer).

5. Control – Manages and coordinates all operations.

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⚙️ Main Components of a Computer

1. Hardware – The physical parts:

• Input Devices: Keyboard, Mouse, Scanner, Mic

• Output Devices: Monitor, Printer, Speakers

• Storage Devices: Hard Disk, SSD, CD/DVD, USB

• Processing Unit:

  • CPU (Central Processing Unit): Brain of the computer

    • ALU (Arithmetic Logic Unit): Performs calculations

    • CU (Control Unit): Directs operations

• Memory:

  • RAM (Random Access Memory) – Temporary memory

  • ROM (Read-Only Memory) – Permanent built-in instructions

• Motherboard – Main circuit board connecting all parts

• Power Supply Unit (SMPS) – Provides power

2. Software – Set of instructions:

• System Software: Operating Systems (Windows, macOS, Linux)

• Application Software: MS Office, Browsers, Games

• Utility Software: Antivirus, Disk Cleanup

• Programming Software: Python, Java, IDEs (VS Code)

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💻 Types of Computers

A. By Size & Power

1. Supercomputer – Fastest, for scientific research

2. Mainframe – Large organizations, banking

3. Minicomputer – Mid-size, business use

4. Microcomputer – Common PCs, laptops

5. Embedded Systems – Found in washing machines, ATMs

B. By Purpose

• General-purpose – PCs, Laptops

• Special-purpose – Robotics, medical devices

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🔗 Types of Computer Connections

• Wired – LAN, Ethernet

• Wireless – Wi-Fi, Bluetooth, Infrared

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🧠 Generations of Computers

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🧮 Number Systems in Computers

• Binary (Base-2) – 0, 1 (used internally)

• Decimal (Base-10) – Human use

• Octal (Base-8) – Used in older systems

• Hexadecimal (Base-16) – Compact binary representation

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🛡️ Computer Security

• Viruses, Malware – Harmful software

• Antivirus Software – Protects data

• Firewalls – Prevent unauthorized access

• Encryption – Secures data

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🌐 Internet and Networking

• Internet – Global connection of networks

• IP Address – Unique ID of a device

• Web Browser – Software to access web (Chrome, Firefox)

• Email, Cloud Computing, Social Media

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📱 Modern Trends in Computing

• Artificial Intelligence (AI)

• Machine Learning (ML)

• Cloud Computing

• Quantum Computing

• Edge Computing

• Internet of Things (IoT)

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🧾 Summary Table