Operating Systems and Utility Software
What system software is
System software is the software that runs and manages the computer itself and provides a platform for other programs. It is different from application software (programs the user uses to do tasks, like a browser or word processor). The two main types are the operating system and utility software.
The operating system (OS)
The operating system manages the hardware and provides services so applications and users can work. Examples: Windows, macOS, Linux, Android, iOS. Its main jobs:
- Memory management – decides where programs and data go in RAM, and moves data to/from virtual memory.
- Processor (process) management – schedules which tasks the CPU works on and when, so several programs appear to run at once (multitasking).
- Input/output (device) management – controls communication with hardware (keyboard, printer, storage) using device drivers.
- File management – organises files and folders; handles saving, opening, moving and deleting.
- User management & security – handles user accounts, logins and access permissions.
- Providing a user interface (UI) – e.g. a graphical interface (GUI) with windows and icons, or a command-line interface.
Device drivers
A driver is software that lets the OS communicate with a specific piece of hardware. Without the right driver, a device (e.g. a printer) won't work correctly.
Utility software
Utility software helps maintain, optimise and protect the computer. Common utilities:
| Utility | Purpose |
|---|---|
| Antivirus / anti-malware | Scans for and removes malicious software |
| Firewall | Controls network traffic in/out of the computer |
| Backup | Makes copies of files so they can be restored |
| Compression | Reduces file sizes to save space |
| Disk defragmentation | Reorganises files on a magnetic hard drive so they're stored together, speeding up access |
| Disk clean-up | Removes temporary/unwanted files to free space |
| Encryption | Scrambles data to keep it secure |
(Defragmentation mainly helps magnetic HDDs; SSDs don't need it and shouldn't be defragmented.)
Worked example
A user's magnetic hard drive has become slow because files are scattered in fragments across it. Which utility helps?
- Disk defragmentation — it reorganises the fragments so each file's data is stored together, speeding up read times. ✓
Common mistakes
- Confusing system software (OS, utilities) with application software (Word, games, browsers).
- Saying the OS "runs applications" only — it also manages memory, processor, I/O, files and users.
- Thinking an SSD benefits from defragmentation — it doesn't.
Exam tips
- Learn the OS's management roles: memory, processor, I/O, file, user/security, and the UI.
- Be able to name a utility and its purpose (defrag, backup, antivirus, compression).
- Remember drivers connect the OS to specific hardware.
Key facts to remember
- System software runs the computer; application software lets users do tasks.
- The OS manages memory, the processor, input/output, files, users/security and provides the user interface.
- Utility software maintains the system: antivirus, firewall, backup, compression, defragmentation, disk clean-up, encryption.