Fiducia TogetherSubprogram
A named, reusable block of code. Procedures and functions, and the difference.
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.
What it is
A subprogram is a named block performing a task. A function returns a value; a procedure does not. Parameters are the inputs it declares; arguments are the values passed in.
Where it applies
GCSE and A Level computer science.
How it works
Subprograms give reuse, readability, easier testing and local scope — variables inside are not visible outside, which prevents accidental interference.
They are decomposition made concrete.
How to use it in your work
When asked for advantages, give three specific ones rather than "it is neater": reuse without rewriting, easier to test in isolation, easier to change in one place.
Be precise about parameter versus argument if your board uses both terms.
Where to get help
Your teacher and your board's specification — the pseudocode and the required language differ between boards. Bitesize covers the concepts; the computer science song runs the topics.
Revise this with a song
These are ours. We write revision songs because a lot of people remember a tune when they cannot remember a page, and because revising out loud in the kitchen beats staring at a highlighter.
- The Computer Science Song The GCSE computer science topics, set to music.
Where to read more
Last reviewed 2026-08-28 by Fiducia Together · Next review due 2027-08-28
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.