The internet is a network of networks: millions of them, joined by routers that pass data along towards where it's going. Every device on it has an IP address, like 93.184.215.14, that says where to deliver data. (The newer IPv6 addresses are longer, because the old kind ran out.)
Data doesn't travel as one big lump. It's cut into packets of up to about 1,500 bytes, each labelled with where it's from and where it's going. Each router looks at a packet's destination and sends it one hop closer; packets from the same message can take different routes and arrive out of order.
People don't remember numbers, so DNS (the domain name system) works like a phone book: your computer asks a DNS server for the IP address of a name like quackgames.net, then connects to that address.
TCP makes the delivery reliable. It numbers the packets, has the receiver confirm what arrived, resends anything lost and puts everything back in order. (UDP skips all that for speed, which suits video calls and online games, where a late packet is useless anyway.)
On top of that, the web uses HTTP. Your browser sends a request ("GET /learn"), and the server sends back a response: a status code like 200 (OK) or 404 (not found), then the page itself. HTTPS is HTTP inside an encrypted connection, so nobody along the route can read or change it. That's the padlock in the address bar.
You type a web address and press Enter. Put the steps in order.
| IP address | Where to deliver data, like 93.184.215.14. |
|---|---|
| Packet | A small labelled piece of data. |
| Router | Passes packets one hop closer. |
| DNS | Names → IP addresses. |
| TCP / UDP | Reliable and in order / fast, no resending. |
| HTTP(S) | Requests and responses of the web (encrypted with S). |