Fiducia TogetherProtocols and layers
Agreed rules that let different systems talk, organised in layers.
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 protocol is a set of rules for communication. Common ones: TCP/IP, HTTP and HTTPS, FTP, SMTP, IMAP and POP, DHCP. Layering separates concerns so each layer can change independently.
Where it applies
GCSE and A Level computer science.
How it works
Layering means a change to the physical medium — copper to fibre — needs no change to HTTP. That independence is the reason for it, and it is the mark-scheme answer.
TCP handles reliable delivery and reassembly; IP handles addressing and routing.
How to use it in your work
Learn which protocol does what, in one clause each. Questions give a scenario and ask which applies.
HTTPS adds encryption. Say encryption, not "it is secure".
For "why use layers", give the independence answer plus interoperability between manufacturers.
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.