GET, POST are some of the HTTP methods negotiated by the specification.
Besides this there are also PUT, PATCH, HEAD, DELETE etc ..
GET method
GET adds it to the URL and makes a request
POST method
POST method is included in body of request.
GET adds directly to the URL so you can see the parameters with your eyes.
Since POST is included in body, it can not be seen with eyes.
There are different specifications when requesting with GET and POST, such as being able to send in binary, size restriction, etc.