HTTP Methods (GET, POST, PUT, DELETE)

HTTP methods (also called verbs) tell the server what action a request wants. GET reads a resource, POST creates one or submits data, PUT replaces a resource, PATCH changes part of it and DELETE removes it. HEAD and OPTIONS ask for headers and allowed methods.

GET puts its parameters in the URL, can be cached and bookmarked, and should never change data. POST sends data in the request body and is used for forms, logins and uploads. GET, PUT and DELETE are idempotent (repeating them has the same effect as doing them once); POST is not. REST APIs map these methods to create, read, update and delete operations.