How the Internet Works

The Internet is a global system of interconnected computer networks that uses the Internet protocol suite to communicate between networks and devices. It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies.

The Internet carries a vast range of information resources and services, such as the interlinked hypertext documents and applications of the World Wide Web, electronic mail, telephony, and file sharing. The origins of the Internet date back to research commissioned by the United States government in the 1960s to build robust, fault-tolerant communication networks.

When you type a web address into your browser, a complex series of events happens almost instantly. Your computer sends a request to a Domain Name System server, which translates the human-readable address into a numerical IP address. Your request is then broken into small packets of data and sent across the network, potentially traveling through dozens of different computers and cables before reaching its destination.

The server at the destination receives your request, processes it, and sends back the response — the web page you requested — in packets that travel back to your computer. Your browser reassembles these packets into the page you see on your screen.

All of this happens in milliseconds, across potentially thousands of kilometers, through a system designed to be resilient even if parts of it are damaged or destroyed. It is one of the most remarkable engineering achievements in human history.