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Theory Notes/🖥️ Topic 1: System Technologies/10.1.5
10.1.5Grade 10

Functions of an Operating System

The operating system is the most important piece of software on any device — nothing else can run without it. This subtopic covers its core jobs at a general level.

An operating system (OS) is system software that manages computer hardware and software resources, and provides common services for application programs.

The general functions of any operating system include:

  • Providing a user interface — the way a user interacts with the computer, e.g. a Graphical User Interface (GUI) with icons and windows, or a Command Line Interface (CLI) using typed commands.
  • Loading and running programs — locating a program on secondary storage, loading it into RAM, and starting its execution.
  • Managing resources — allocating CPU time, RAM, storage space and peripheral access fairly and efficiently among all running programs.
  • Acting as an interface between hardware and application programs — application software doesn't talk to hardware directly; it makes requests to the OS, which then communicates with the hardware via drivers.

Example

When you open a word processor: the OS locates the program file, loads it into RAM, allocates it a share of CPU time, lets it draw its window via the GUI, and handles every keystroke you type by passing it from the keyboard driver to the application.

💡 Exam Tip

At Grade 10 level you're expected to know these functions in general terms. Grade 11 and 12 go much deeper into how the OS actually manages memory, processing and I/O — so this subtopic is the foundation, not the full picture.