GET is the simplest HTTP method, and its main job in life is to ask the server to get a resource and send it back. That resource might be an HTML page, a JPEG, a PDF, etc. Doesn’t matter. The point of GET is to get something back from the server.
POST is a more powerful request. It’s like a GET plus plus. With POST, you can request something and at the same time send form data to the server (later in this chapter we’ll see what the server might do with that data).