HTTP status code
Also called: Status code, Response code
A three-digit number in every server response: 200 means OK, 404 not found, 500 server error.
Definition
Status codes are grouped: 2xx success, 3xx redirect, 4xx client errors (bad request, unauthorized, not found), 5xx server errors. Testers read them in DevTools or proxy tools to understand failures and to check that the app shows the right message for each.
In practice
The app says "Wrong password" but the network tab shows a 500, so the real problem is a server error, not the password.
Learn it in context
Lessons that use this term.