ALU - GCSE Computer Science Definition
Reviewed by: Robert Hampton
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What is the ALU?
In GCSE Computer Science, the ALU (Arithmetic Logic Unit) is defined as a component of the CPU, responsible for performing arithmetic operations and logical decisions.
Arithmetic operations - performing operations and calculations on numbers (e.g. addition or subtraction)
Logical decisions - making decisions on a set of predefined conditions (e.g. comparisons)
The ALU plays a crucial role in the execute stage of the fetch-decode-execute cycle.

ALU Revision Resources to Ace Your Exams
Explore the ALU in more detail and master other key related terms such as the control unit (CU) and cache in our revision note pages here:
CPU components & their function (OCR GCSE Computer Science)
CPU components & their function (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
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