How the Internet Works

Meet Kite Studio: twenty designers on one office floor, a rack with a switch and a router, a Wi-Fi access point on the ceiling and one fibre line to the outside world. This course follows that office from its first packet to a full address plan. We start with the question every engineer should be able to answer on a whiteboard: when Asha opens a website on her studio laptop, what actually happens?

The rule

The internet is a network of networks, passing packets hop by hop.

A network of networks. There is no single "internet" machine. Kite Studio's office is one small network. Its internet service provider (ISP) runs a much larger one. That ISP connects to other ISPs, cloud providers and content networks, often at shared meeting points called internet exchange points. The internet is simply all of these independently owned networks agreeing to carry each other's traffic.

Packets. Nothing crosses the internet as one big lump. A web page, a photo or a video call is chopped into small pieces called packets. Each packet carries a label with the address it came from and the address it is going to.

Hop by hop. No device knows the whole path. A router looks at a packet's destination, picks the best next router it knows of, and hands the packet on. Each handover is a hop. Dozens of routers, each making one small local decision, add up to a journey across the world.

The shortcut

When anyone asks "how does it get there?", answer with four questions in a fixed order: Name → Address → Connection → Hops. Which name did the user type, what address does it turn into, how do the two ends agree to talk, and which networks carry the packets between them?

The common mistake is picturing a direct wire between Asha and the server. There is no such wire. Her packets share links with millions of other people's packets, and each router along the way only decides the next step. That is exactly why the internet survives failures: if one link breaks, routers simply start choosing a different next hop.

Drills

Answer fast — trust the rule.

Remember

• The internet is a network of networks, passing packets hop by hop.
• To explain any request, go Name → Address → Connection → Hops.
• There is no direct wire: packets share links, and each router only picks the next step.