Cookies, Sessions, and Tokens

Part of the Web course

HTTP has no memory. Every single request you send is treated by the server as if it had never seen you before, even if you sent the exact same request five seconds ago. That is a real problem the moment you need a server to know "this request is from the same person who just logged in." Without some way to carry that fact forward, every click on a website would ask you to log in again.

Cookies, sessions, and tokens are the three answers the web has settled on for that problem. They solve the same thing, "remember who this request is from," in three different ways, each with its own tradeoffs. By the end of this lesson you will be able to look at a real login flow and say which of the three it is using, and why. ...