What does OCR 1.5 Systems software cover?

It covers the purpose and functions of the operating system (providing a user interface, memory management and multitasking, peripheral management with device drivers, user management and file management) and the purpose of utility software (encryption software, defragmentation software, data compression and backup utilities, including full and incremental backups). It is examined in Paper J277/01.

What are the main functions of an operating system?

The operating system provides a user interface, performs memory management (allocating RAM to programs and managing virtual memory), handles multitasking (sharing processor time), carries out peripheral management using device drivers, performs user management (accounts, logins, access rights) and file management (organising, saving, moving and deleting files). It manages the hardware and provides a platform for applications.

What is a device driver?

A device driver is software that translates between the operating system and a specific peripheral device, such as a printer or keyboard, so that the device works correctly. Peripheral management, one function of the operating system, uses drivers to control input and output devices.

What does defragmentation do?

Over time, files on a magnetic hard disk become fragmented, with parts stored in different physical locations, which slows access because the read/write head must move to several places. Defragmentation software reorganises the files so each is stored together (contiguously) and free space is gathered, speeding up access. It benefits magnetic disks but is not needed for solid-state drives.

What is the difference between a full and an incremental backup?

A full backup copies all the selected files every time, so it is simple and quick to restore from but takes the most time and storage. An incremental backup copies only the files that have changed since the last backup, so each backup is faster and smaller, but restoring is slower because the last full backup and every incremental backup since must be combined.

EnglandComputer Science

OCR GCSE Computer Science 1.5 Systems software: the operating system and utility software

A deep-dive OCR GCSE Computer Science guide to topic 1.5 Systems software. Covers the purpose and functions of the operating system (user interface, memory management, multitasking, peripheral management and drivers, user management, file management) and utility software (encryption, defragmentation, compression, full and incremental backups), with the definitions Paper 1 rewards.

Generated by Claude Opus 4.811 min readJ277 1.5Updated 2026-06-02

Reviewed by: AI editorial process; not yet individually human-reviewed

Jump to a section

What topic 1.5 actually demands
The operating system
Utility software
Check your knowledge

What topic 1.5 actually demands

Systems software is the software that runs and maintains the computer itself, as opposed to applications that do work for the user. It is a definition-heavy topic examined in Paper 1, where the marks reward precise functions and clear descriptions. You need to know the purpose and functions of the operating system and the purpose of the named utility software.

This guide ties together the two dot-point pages for the topic.

The operating system

The operating system manages the hardware and resources and provides a platform for applications. Its functions are: a user interface (so the user can interact), memory management (allocating RAM to programs, keeping their data separate, managing virtual memory), multitasking (sharing processor time so several programs run at once), peripheral management (controlling input/output devices using device drivers, software that translates between the OS and a specific device), user management (accounts, logins, access rights) and file management (organising, saving, moving and deleting files).

Utility software

Utility software performs maintenance and housekeeping. Encryption software scrambles data with a key so it cannot be read without it. Defragmentation software reorganises a fragmented magnetic disk so files are contiguous and faster to access (not needed for SSDs). Compression software reduces file sizes. Backup software copies files so they can be restored: a full backup copies everything every time (simple restore, large and slow), while an incremental backup copies only changes since the last backup (small and fast, but slower to restore).

Check your knowledge

A mix of recall and applied questions covering topic 1.5. Attempt them, then check against the solutions.

State four functions of an operating system. (4 marks)
State what a device driver does. (1 mark)
Explain what memory management involves. (2 marks)
State what utility software is. (1 mark)
Explain why defragmentation speeds up a magnetic hard disk. (2 marks)
State why defragmentation is not needed for a solid-state drive. (1 mark)
State one advantage of a full backup. (1 mark)
State one advantage of an incremental backup. (1 mark)

Solutions

Q1: Any four of: providing a user interface, memory management, multitasking, peripheral management (drivers), user management, file management.
Q2: It is software that translates between the operating system and a specific device so the device works correctly.
Q3: Allocating RAM to each running program and keeping their data separate, freeing memory when programs close, and managing virtual memory.
Q4: Systems software that performs maintenance and housekeeping tasks to keep the computer running smoothly.
Q5: It reorganises fragmented files so each is stored contiguously, so the read/write head moves less and files are read faster.
Q6: A solid-state drive has no moving read/write head, so the physical position of file parts does not affect access speed.
Q7: Restoring is simple and quick because all the files are in one backup.
Q8: Each backup is faster and uses less storage because only the files changed since the last backup are copied.

Sources & how we know this

OCR GCSE (9-1) Computer Science (J277) specification — OCR (2020)