How the Web Works: Requests, Cookies and Sessions

By the end of this lesson you can describe an HTTP request and response, read the common status codes, explain what cookies and sessions do, explain why a session cookie must be kept secret, and explain in plain words where most web security bugs come from and how sites defend against them. There is no lab in this lesson. The web messages are shown as plain text so you can read exactly what a browser and a server say to each other; the example shop shop.lab.internal exists only inside Purple Edge labs.