Learning Objectives:

• ✅ Define what an Operating System (OS) is.

• ✅ Explain the main functions of an OS.

• ✅ Identify examples of different Operating Systems.

• ✅ Understand why an OS is important in computing.

Operating systems

• Use the white board and write down what operating systems have you heard about or used.

Commonly used operating systems

• Windows xp/8/10/11

• iOS

• Linux

• Unix

• macOS

• Ubuntu

• Chrome

• Android

• Raspberry Pi

Key functions of a operating system

The key 5 functions of an OS

• Memory Management – Allocates RAM for running programs.

• Process Management (Multitasking) – Handles multiple applications.

• Peripheral Management – Controls hardware (printers, keyboards, etc.).

• File Management – Organizes and stores files.

• User Interface – Allows interaction (CLI or GUI).

Memory Management

• The OS allocates memory between the different programs that are open at the same time

• Programmers and users do not need to know where in memory data is being held – it is the purpose of the Operating System to do this

Process Management (Multitasking)

• Process management and multitasking are fundamental to modern operating systems, enabling computers to run multiple programs concurrently by rapidly switching between them, giving the illusion of simultaneous execution.

• Graphical User Interface (GUI).

• Command Line Interface (CLI).

• Natural Language Interface (NLI).

• Menu-Based Interface.
  

User interfaces

There are 4 types of user interfaces.

1. Graphical User Interface (GUI)

• Uses windows, icons, menus, and a pointer (WIMP).

• Easy to use, intuitive, and visually appealing.

• Examples: Windows, macOS, Linux with GNOME/KDE.

2. Command Line Interface (CLI)

• Text-based, requires typing commands.

• Fast and efficient for experienced users.

• Examples: Linux Terminal, Windows Command Prompt, PowerShell.

3. Natural Language Interface (NLI)

• Allows users to interact using spoken or written language.

• AI-powered, understands human commands.

• Examples: Siri, Alexa, Google Assistant.

​4. Menu-Based Interface

• Presents options in a list or hierarchical menu format.

• Simple and easy to navigate.

• Examples: ATMs, mobile phone settings menus.