OCR J277 · Component 01 · §1.5 · Paper 1

§1.5 Systems Software

What does the operating system actually do — and what is utility software for?

Systems software is software that manages the computer's hardware and creates an environment where application software can run. The operating system is the central layer — without it, there is no user interface, no way to run programs, no file system, and no way to control peripherals. Every action you take on a computer (opening a file, connecting a printer, logging in) is handled by one of the OS's five core functions.

Utility software sits on top of the OS and handles specific housekeeping tasks the OS doesn't do itself — things like encrypting files, defragmenting a hard drive, or compressing data. The boundary between OS and utility is a key OCR discriminator: the exam rewards students who can distinguish the two and explain why utilities are a separate category rather than built into the OS core.

Describe the role of memory management in an operating system and explain how it allows multitasking. (4 marks) — Then: a student's hard drive is running slowly after months of use. Suggest a utility program they should run, explain what it does, and why it improves performance.

OS functions — one job each

User interface — provides the interface between user and hardware (GUI, CLI)

Memory management — allocates RAM to applications; enables multitasking; manages virtual memory

Peripheral management — handles communication with devices via drivers

User management — accounts, login, access rights, security

File management — naming, organising, moving, saving, deleting files

What students must understand

Systems software: manages hardware and provides a platform for applications
Operating system as the central systems software layer — without it, the computer cannot function
User interface: provides the way users interact (GUI with windows/icons, or CLI with typed commands)
Memory management: allocates RAM to programs; tracks which memory each process uses; enables multitasking by switching rapidly between applications; uses virtual memory when RAM is full
Peripheral management: coordinates communication between CPU and devices via device drivers; different drivers for different hardware
User management: creates and manages accounts; assigns access rights and permissions; enforces security (login credentials)
File management: organises files in a directory structure; handles naming, moving, copying, saving, deleting
Utility software: performs additional housekeeping tasks not covered by the OS core
Encryption utility: scrambles files so only authorised users with the key can read them
Defragmentation: reorganises fragmented data on a magnetic hard drive so related blocks are stored contiguously — speeds up access (not needed/appropriate for SSDs)
Data compression utility: reduces file sizes by encoding data more efficiently; useful for storage and transfer

Diagrams

A grid of numbered coloured blocks scattered across a disk, representing fragmented files — A fragmented disk holds files in scattered blocks. Defragmentation reorders them so each file is contiguous and faster to read.

Diagrams: PG Online (Paul Long), OCR J277 textbook. Used under the school site licence.

Linking questions

What is RAM, and why is memory management needed? → §1.2 Memory and Storage
How do access rights connect to security and user management? → §1.4 Network Security

Practice

§1.5 Systems Software practice questions — 3 printable question sets from the PG Online textbook pack

Video Support

Craig'n'Dave — OCR J277

The purpose of operating systems

Operating systems 1

Operating systems 2

Utility system software