Introduction to Computing and Computer Systems

Computing

Computing is the automatic processing of information with computers.

Input and Output

Input: Data entered into the computer.
CPU: Processes the information.
Output: The processed information is displayed.

Binary System

Computers use the binary system (0 and 1).
Bit (b): Smallest unit of information (0 or 1).
Byte (B): Group of 8 bits. Example: 1010 0001
Characters are usually expressed with 1 B (8 bits).

Character Encoding

ASCII (American Standard Code for Information Interchange): Represents characters using binary code.
ISO-8859-1: An extension of ASCII, uses 1 byte for characters. Example: A = 0100 0001 (65), = 0111 1110 (126)

Hardware

The physical components of a computer.

Internal Components

• Motherboard
• CPU

External Devices (Peripherals)

• Input: Webcam, mouse, microphone, keyboard.
• Output: Speakers, Wi-Fi, monitor, pendrive.

Key Hardware Components

• CPU (Central Processing Unit): Executes program instructions.
• Main Memory/RAM: Stores data and instructions. Volatile.
• Hard Disk/SSD: Stores programs and data. Non-volatile.
• Motherboard: Connects all components.
• Graphics Card: Processes images for the monitor.
• Expansion Cards: Provide extra functionality (e.g., Wi-Fi).

Software

The set of instructions for the processor.

Operating System

• Examples: Windows, macOS, Linux.

Applications

Programs that perform specific tasks.

• Utilities: Compressors, antivirus, backup.
• Communications: Browsers, email, messaging.
• Office: PDF viewers, word processors, spreadsheets.
• Multimedia: Image, audio, and video editors.
• Others: CAD, games.

Interaction

User -> Application Software -> Operating System -> Hardware