🪟 Computers & Networks

Operating Systems & Files

⏱ 2 hr3 topicsInteractive

🎯 By the end: You can explain the functions of an OS, name its types, tell a CUI from a GUI, read a file path & extension, and contrast open-source with proprietary OS.

The most important software on any computer is its Operating System (OS) — the program that runs everything else. Without it, the hardware just sits there. This chapter explains what the OS does and how it organises your files.

1What an OS does & its types

An operating system is system software that manages the computer and lets you use it. Its main jobs:

Manages memory — decides what goes in RAM.
Manages processes — runs your programs.
Manages files & storage — saves and finds your data.
Manages devices — talks to the keyboard, printer, etc.
Provides a user interface — how you interact with the computer.

Types of OS

Type	Means
Single-user	One person at a time (most home PCs)
Multi-user	Many users share one system at once (a server)
Multi-tasking	Runs several programs at the same time
Real-time	Responds instantly — used in robots, ATMs, medical devices
Distributed	Spreads work across many connected computers

Key points

An OS is system software that manages memory, processes, files, devices and the user interface.
Types: single-user, multi-user, multi-tasking, real-time and distributed.
Real-time OS respond instantly (robots, ATMs); multi-tasking runs several programs at once.

2CUI vs GUI

The OS gives you a user interface — a way to give it commands. Two kinds:

	CUI (Command User Interface)	GUI (Graphical User Interface)
You interact by	Typing text commands	Clicking icons, menus, windows
Example	Linux terminal, MS-DOS	Windows, macOS, Android
Ease of use	Harder (must remember commands)	Easier (point and click)

GUIs use the WIMP idea — Windows, Icons, Menus, Pointer — which makes computers easy for everyone. CUIs are powerful for experts who type commands.

Key points

A CUI (command interface) needs typed commands; a GUI uses icons, menus and windows (point & click).
Examples: CUI = Linux terminal/MS-DOS; GUI = Windows, macOS, Android.
GUIs are easier for everyone; CUIs are powerful for experts.

3Files, folders & open-source vs proprietary

The OS stores data as files, organised in folders (directories), which can be nested. The location of a file is its path:

C:\Users\Asha\Documents\report.docx
  |     |     |       |          |
drive folders ...               file name + extension

A file extension (after the dot) tells you the file's type: .docx (Word), .jpg (image), .mp3 (audio), .py (Python).

Open-source vs proprietary OS

	Open-source	Proprietary
Source code	Free to view & change	Owned & hidden by a company
Cost	Usually free	Usually paid
Example	Linux	Windows, macOS

Key points

Files are stored in folders (directories); a file's location is its path.
A file extension (.docx, .jpg, .py) tells you the file's type.
Open-source OS (Linux) share their code freely; proprietary OS (Windows, macOS) are company-owned and usually paid.

★ Practical: explore your OS

On a computer you use:

Name the operating system and say whether it uses a CUI or GUI.
Find a document and write down its full path and its file extension.
Create a folder, put two files in it, and rename one.
Name one open-source OS and one proprietary OS.

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