514 Web communication protocols

Web communication relies on standardised protocols that define how devices connect, transmit, and secure data across the internet.

Outline

This section introduces the key protocols that underpin web communication. Students explore how data is transmitted using HTTP and HTTPS, how addressing and routing occur through IP and DNS, and how other protocols support services like file transfer and email. Understanding these protocols provides a foundation for web security, performance, and connectivity.

Targets

In this topic, students learn to:

• Identify key web protocols and their roles in data transfer

• Describe the structure and function of data packets

• Explain how protocols interact with port numbers and services

• Compare secure and insecure protocols (e.g. FTP vs SFTP)

• Recognise the role of DNS and IP addressing in internet communication

Glossary

Term	Definition
Protocol	A defined set of rules for how devices communicate over a network
Port	A numbered channel on a device used to route specific types of traffic
IP address	A unique identifier for a device on a network (IPv4 or IPv6)
DNS	Domain Name System; translates human-readable domain names into IP addresses
HTTP/HTTPS	Protocols used for requesting and delivering web content; HTTPS adds encryption
TCP/IP	A suite of protocols that define how data is formatted and transmitted across networks
FTP/SFTP	Protocols used for file transfer; SFTP includes secure encryption
SMTP/POP3/IMAP	Protocols used to send and retrieve email messages

Overview

Web protocols are the invisible infrastructure of online communication. From the moment a user types a URL into a browser, a chain of protocol-driven interactions takes place to locate the destination server, request data, and display it securely in the browser.

This section helps students build a mental model of how these protocols work together, what role each plays, and how they are used in web development. The protocols covered in this section will also support future learning in back-end development, security, and API design.