What is System Software?
Software can be split into two main categories: system software and application software. System software is the layer of software that controls and manages the computer's hardware, creating a foundation that other software can run on.
Without system software, the hardware components — the CPU, RAM, storage devices, and input/output devices — would just be an expensive collection of electronics that cannot do anything useful.
The Operating System
The most important piece of system software is the Operating System (OS). It manages all of the computer's resources and acts as the go-between for the hardware and the software running on top of it.
Examples of operating systems include:
- Windows (Microsoft) — most common on desktop PCs
- macOS (Apple) — used on Macs
- Linux — open-source, used on servers and developer machines
- Android / iOS — operating systems for smartphones and tablets
When you turn on a computer, the first thing that loads is the operating system. All other programs — your browser, games, and apps — run on top of it.
What Does the OS Do?
The operating system has many responsibilities:
| Task | Description |
|---|---|
| Process management | Decides which programs get CPU time and when |
| Memory management | Controls which program uses which part of RAM |
| File management | Organises files into folders and controls access |
| Device management | Communicates with printers, keyboards, and other peripherals |
| User interface | Provides the desktop, windows, and menus |
| Security | Manages user accounts and permissions |
Other Types of System Software
Beyond the OS, there are other important types of system software:
- Device drivers — small programs that allow the OS to communicate with specific hardware (e.g. a printer driver)
- Utility programs — tools that help maintain and optimise the system, such as antivirus software, disk defragmenters, and backup tools
- BIOS/UEFI — the first code that runs when you switch on a computer, which initialises the hardware and loads the OS
Think of the operating system like the management team of a company. The workers (applications) do specific jobs, but the management coordinates everything, allocates resources, and makes sure nothing conflicts.
Practice Problems
Describe three tasks performed by an operating system.
Show answer
What is a device driver and why is it needed?