💻 Computer Systems and Organisation

1. Introduction to Computer System

A computer is an electronic device that accepts data as input, processes it, and gives desired output. The physical components are called Hardware, while the set of instructions that runs the hardware is called Software.

2. Basic Computer Organisation (Von Neumann Architecture)

Core Components

1. Input Unit: Devices used to enter data (Keyboard, Mouse, Scanner).

2. CPU (Central Processing Unit): The brain of the computer. Contains ALU (Arithmetic Logic Unit) and CU (Control Unit).

3. Memory Unit: Stores data. Primary memory (RAM, ROM) and Secondary memory (HDD, SSD).

4. Output Unit: Devices that display results (Monitor, Printer).

3. Types of Memory

RAM (Random Access Memory): Volatile memory. Loses data when power is turned off. Used for active tasks.
ROM (Read Only Memory): Non-volatile memory. Retains data even without power. Contains booting instructions (BIOS).
Cache Memory: Extremely fast memory located close to the CPU to speed up processing.

4. Software Classification

Types of Software

System Software: Controls internal computer operations (e.g., Operating Systems like Windows, Linux, Device Drivers, Language Translators).

Application Software: Designed for specific user tasks (e.g., MS Word, Web Browsers, Games).

Utility Software: Assists in maintenance of the computer (e.g., Antivirus, Disk Defragmenter).