Names for people, numbers for machines

You type shop.example into your browser. Names are for people: easy to remember, easy to type, and they stay the same when the shop moves to new servers.

Computers find each other by IP address, like 203.0.113.10. So before your browser can send a single byte to the shop, it has to turn the name into an address. Watch Alice’s laptop ask first, then connect.

That lookup is the job of the Domain Name System, DNS. It runs before almost every connection you make, and you rarely notice it. This lesson opens it up.