Computer Studies (AKU-CS)
Topic 1 of 7Aga Khan Board

Introduction to Computers

Computer basics and components

A computer is an electronic device that processes data according to instructions. Computers have evolved through five generations:

  • 1st Generation (1940s–50s): Used vacuum tubes. Huge, expensive.
  • 2nd Generation (1950s–60s): Used transistors. Smaller, faster.
  • 3rd Generation (1960s–70s): Used integrated circuits (ICs).
  • 4th Generation (1970s–present): Used microprocessors — entire CPU on one chip.
  • 5th Generation (present–future): Based on artificial intelligence.

  • Every computer has hardware — the physical components:

  • CPU — the brain. Executes all instructions.
  • RAM — temporary memory. Loses data when power is off.
  • Storage (HDD/SSD) — permanent memory for files and programs.
  • Input devices: keyboard, mouse, microphone
  • Output devices: monitor, printer, speakers

  • Software tells hardware what to do:

  • System software — manages hardware. Example: Windows, macOS, Linux, Android.
  • Application software — for specific tasks. Example: MS Word, Chrome, WhatsApp.

  • An operating system (OS) is the most important system software — it manages files, memory, and processes.

    Key Points to Remember

    • 1Computer generations
    • 2Hardware components
    • 3Software types
    • 4Operating systems

    Pakistan Example

    From PTCL Landlines to 5G — Pakistan's Tech Leap

    Pakistan went from mechanical calculators in government offices to 4th-generation smartphones. A rickshaw driver in Lahore uses an Android smartphone (with a microprocessor) running Careem — the same generational leap that took the world 70 years, now sitting in his pocket.

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