Let's talk about Lilo & stitch, we'll get to code later. First of all did you know lilo is Hawaiian for lost, so the title of most peoples beloved childhood show means lost and put together.
The different method like GET and POST are ways to retrieve and send data to the server. PATCH is not so different it modifies an existing resource not unlike PUT. But PATCH can send back specific changes back to the resource. To go deeper it shares a set of instructions on how the resource should be changed.