The Internet: History & How It Works
Where the Internet came from and the TCP/IP machinery that moves data around the world.
History of the Internet
The Internet did not appear overnight. It grew in distinct eras, each one adding a capability that made the next possible.
| Era | Milestone |
|---|---|
| 1960s | ARPANET launched by the US Department of Defense — the first network connecting universities and research centres. |
| 1970s | Email is invented; the TCP/IP protocol is developed to standardise communication across different networks. |
| 1980s | The Internet expands beyond academia; Tim Berners-Lee invents the World Wide Web (1989). |
| 1990s | The Mosaic browser launches; rapid public adoption; e-commerce and search engines emerge. |
| 2000s | Social media boom (Myspace, Facebook); smartphones and the mobile Internet revolution. |
| 2020s | AI, IoT, 5G, Web3, edge computing and large language models reshape the Internet. |
How Does the Internet Work?
The Internet is a massive global network of computers and devices interconnected via TCP/IP (Transmission Control Protocol / Internet Protocol), enabling the exchange of data worldwide.
Every device on the Internet has a unique IP address — a numeric label used to route data between machines.
Scale in 2025: 5.4 billion+ users, and roughly 29 billion connected IoT devices.
How data travels
- Request sent — you type a URL and your device sends a data request.
- DNS lookup — DNS translates the domain name into an IP address.
- Routing — routers direct packets across interconnected networks.
- Server reply — the web server sends back the requested content.
- Rendered — your browser assembles and displays the web page.
Modern connections increasingly use HTTP/3 over the QUIC protocol, and IPv6 addressing.