One request, a stack of problems

Alice types curl http://shop.example/. Her laptop now has to get 75 bytes of text to a server in another city, and get a page back.

That one job hides a pile of smaller ones. Turn bits into electrical signals. Get them to the next box on the wire. Find a route across many networks. Resend anything that gets lost. Deliver it to the right program. Agree on what the bytes mean.

Watch the request travel. It goes down Alice’s stack, growing at every step, crosses the wire as bits, then climbs up the server’s stack, shrinking back to the original 75 bytes. By the end of this lesson you’ll be able to read every block.