The Internet and the World Wide Web

Many people use the terms "Internet" and "World Wide Web" interchangeably, but at A-Level you must understand that they are not the same thing. This lesson clarifies the difference and explores the infrastructure and services that make them work.

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The Internet

The Internet is a global network of interconnected networks — a physical infrastructure of cables (copper, fibre optic), wireless links, routers, switches, and servers that allows billions of devices worldwide to communicate using standardised protocols (primarily TCP/IP).

Key Facts

Aspect	Detail
What it is	A global network infrastructure (hardware + protocols)
Invented	Evolved from ARPANET (late 1960s)
Protocols	TCP/IP
Services carried	Email, file transfer, web, VoIP, streaming, gaming, IoT, and many more
Physical medium	Fibre optic cables (including undersea), copper cables, satellite links, wireless

The Internet is not any single network — it is the interconnection of thousands of networks (ISPs, university networks, government networks, corporate networks, etc.) that agree to exchange traffic.

How Devices Connect to the Internet

1. A home device connects to a local network (via Wi-Fi or Ethernet).
2. The local network connects to an ISP (Internet Service Provider) via a modem/router.
3. The ISP connects to other ISPs and Internet Exchange Points (IXPs) via high-capacity backbone links.
4. Data is routed through multiple networks to reach its destination.

Your Device → Home Router → ISP → Internet Backbone → Destination ISP → Destination Server

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The World Wide Web (WWW)

The World Wide Web is a service (an application) that runs on top of the Internet. It is a collection of interlinked web pages and resources accessed using web browsers via the HTTP/HTTPS protocol.

Key Facts

Aspect	Detail
What it is	A system of interlinked hypertext documents and resources
Invented	Tim Berners-Lee, 1989 (at CERN)
Protocol	HTTP / HTTPS
Access	Via a web browser
Content	Web pages (HTML), images, videos, scripts, APIs
Identification	URLs (Uniform Resource Locators)

Components of the Web

Component	Role
HTML	Markup language for structuring web pages
HTTP/HTTPS	Protocol for requesting and delivering web resources
URLs	Addresses that identify specific resources (e.g. https://www.example.com/page)
Web browsers	Client software that renders web pages (Chrome, Firefox, Safari, Edge)
Web servers	Software that hosts and serves web pages (Apache, Nginx, IIS)
Hyperlinks	Connections between web pages — the "web" of links

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The Difference