Protocols and Standards
intermediate20 minLearning objectives
- Explain the purpose of communication protocols
- Identify common Internet protocols
- Justify the use of appropriate protocols in different scenarios
Learn
AQA 4.7.2 — Protocols
Retrieval: you've studied how a single processor executes instructions - protocols are the rules that let entirely separate computer systems coordinate with each other over a network, which is a genuinely different problem from anything covered inside one machine.
A protocol is an agreed set of rules that lets devices communicate reliably, regardless of who made them or what software they run.
| Protocol | Purpose |
|---|---|
| TCP/IP | The foundational protocol suite of the Internet — breaks data into packets, routes and reassembles them |
| HTTP | Transfers web pages between server and browser |
| HTTPS | HTTP with encryption (TLS/SSL) |
| FTP | Transfers files between computers |
| SMTP | Sends email |
| POP3 / IMAP | Retrieves email from a server |
Why layers of protocols matter
No single protocol does everything. When you load a web page, HTTP handles the request/response, while underneath it, TCP/IP handles breaking that request into packets, addressing them, and routing them across networks. This layered approach means each protocol can be understood, implemented and improved independently.
HTTP vs HTTPS
HTTPS adds encryption on top of HTTP, protecting data in transit from being read or tampered with by anyone intercepting it — essential for anything involving passwords, payment details, or personal data. A browser's padlock icon indicates HTTPS is in use.
Reflection
Why would sending an email (SMTP) and browsing a website (HTTP) need different protocols, rather than one protocol handling everything?