CPU - GCSE Computer Science Definition
Reviewed by: Robert Hampton
Last updated
What is the CPU?
In GCSE Computer Science, the CPU (Central Processing Unit) is defined as the brain of the computer and its job is to take an input, process data and produce an output.

The purpose of the CPU is to fetch, decode and execute instructions and is made up of 4 key components:
Arithmetic Logic Unit (ALU)
Control Unit (CU)
Cache
Registers
The performance of a CPU can be impacted by their shared common characteristics:
Clock Speed
Cache Size
Number of Cores
CPU Revision Resources to Ace Your Exams
Explore the CPU in more detail and master other key related terms such as the fetch-decode-execute cycle in our revision note pages here:
The purpose of the CPU (OCR GCSE Computer Science)
Fetch-execute cycle (AQA GCSE Computer Science)
CPU components & their function (Edexcel GCSE Computer Science)
Challenge yourself with our expertly created topic questions and reinforce your learning with our interactive flashcards.
Examiner-written GCSE Computer Science revision resources that improve your grades 2x
- Written by expert teachers and examiners
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- Everything you need to know, and nothing you don’t

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