Fiducia TogetherMemory and storage
RAM, ROM, virtual memory and secondary storage. Four different things with different jobs.
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
RAM is volatile working memory holding what is currently running. ROM is non-volatile and holds the boot instructions. Secondary storage — HDD, SSD, optical, magnetic tape — holds data permanently. Virtual memory is space on secondary storage used when RAM is full.
Where it applies
GCSE and A Level computer science.
How it works
Volatile means contents are lost when power is removed. That single property explains why RAM cannot be used for storage and why work is lost when a machine crashes.
SSDs are faster, more robust and have no moving parts; HDDs are cheaper per gigabyte. Questions ask you to choose and justify.
How to use it in your work
Never call storage "memory" in an answer. The distinction is explicitly tested.
For device-choice questions, justify on capacity, speed, portability, durability and cost — pick the two that matter for the scenario.
Virtual memory slows a machine because secondary storage is far slower than RAM. Say why, not just that it does.
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.