Operating System Basics – JSS1 Digital Technologies Lesson Note (First Term)

An operating system (OS) is the software that manages the hardware and other software of a computer.

Behavioural objectives

By the end of the lesson, students should be able to:

1. Define an operating system and give examples for computers and phones.
2. State the four main functions of an operating system.
3. Explain what a user interface is and name its two types.
4. Differentiate between a GUI and a CLI.
5. Name and describe the main parts of the desktop.

What is an operating system?

An operating system is a special type of software that controls the hardware, runs other software and lets the user talk to the computer.

• School comparison: a school has teachers, students, cleaners and security guards, and the Principal organises everyone.
• In a computer: the OS is the Principal, so it is called the computer’s manager.
• Hardware it manages: parts you can touch, such as the mouse, keyboard and printer.
• Software it manages: programs such as games and typing tools.
• Without an OS: a computer is a “dead” box of metal and plastic that cannot respond to you.

What are examples of operating systems?

Operating systems are made for computers and for phones.

What are the functions of an operating system?

An operating system has four main functions: hardware management, file management, memory management and providing a user interface.

1. Hardware management

• Control of devices: the OS makes sure the mouse, keyboard and printer work correctly.
• Passing commands: when you click a button, the OS tells the computer what you want to do.

2. File management

• Storage: the OS organises how files, photos and music are stored.
• Folders: it works like a filing cabinet, so you can find your files easily later.

3. Memory management

• Sharing RAM: the OS decides which program uses the RAM (the computer’s working memory) and for how long.
• Smooth running: if you play music while typing, both programs run without crashing.

4. Providing a user interface

• Screen display: the OS creates the pictures, buttons and menus you see on the screen.
• Communication: this is the function that lets people use the computer easily.

What is a user interface?

A user interface is the “bridge” between you and the computer, and it is how you give commands to the machine.

There are two main types: the Graphical User Interface (GUI) and the Command Line Interface (CLI).

Graphical User Interface (GUI)

A GUI lets you control the computer by clicking or touching pictures on the screen.

• WIMP: it uses Windows, Icons, Menus and Pointers.
• How to use it: you use a mouse to click small pictures (icons) to open apps.
• Ease: it is friendly and easy for beginners to learn.
• Examples: Windows 10 and Android.

Command Line Interface (CLI)

A CLI lets you control the computer by typing text commands.

• Appearance: there are no pictures or icons, only text on a black screen.
• How to use it: you type specific commands and press Enter.
• Speed: it is faster for experts.
• Difficulty: it is hard for beginners because many codes must be memorised.
• Example: MS-DOS.

What is the difference between a GUI and a CLI?

What is the desktop?

The desktop is the main screen you see after the computer finishes booting.

• Booting: the process of starting up a computer until the OS is ready to use.
• Comparison: it is like a real desk where you put your books and pens.

What are the main parts of the desktop?

• Icons: small pictures that represent programs or files, such as the Recycle Bin or Google Chrome.
• Taskbar: the long bar at the bottom of the screen that shows which programs are open.
• Start Menu: usually at the bottom-left corner, it is the “doorway” to the apps and settings.
• Wallpaper: the background image that makes the screen look nice.
• Notification area: at the bottom-right near the clock, it shows the battery level, Wi-Fi connection and date.

Evaluation

1. Define an operating system and give two examples for computers and two for phones.
2. List the four main functions of an operating system.
3. What does WIMP stand for?
4. State two differences between a GUI and a CLI.
5. Name the part of the desktop that shows the programs currently open.

Assignment

1. Look at the phone or computer you use. State whether it has a GUI or a CLI, and give a reason.
2. List three icons you can find on a standard computer desktop.