I sent data with GET and the server ignored it. GET asks for something, POST gives something. The method is the verb of the sentence and it decides whether a body means anything.
About 1 min of reading
Send a GET and a POST and see the server treat them differently.
GET the list. The server reads and returns the current records.
Before you run it, say out loud what it will print. Then open the answer.
POST a new record. The server creates it and usually answers with what it made.
Before you run it, say out loud what it will print. Then open the answer.
GET again. The new record is now in the list, proving the POST changed the server.
Before you run it, say out loud what it will print. Then open the answer.
GET means read, POST means create or submit, PUT means replace, DELETE means remove. The method decides whether a body is meaningful. A GET with a body is usually ignored, which is why sending data with GET silently does nothing.
GET promises not to change the server, so it can be cached and retried freely. POST makes no such promise, so a retry might create a second record. That difference is why a browser prefetches GETs but never POSTs.
GET /users HTTP/1.1GET says: give me this resource. It carries no body to speak of. Everything about what you want is in the path and the query string.
POST /users HTTP/1.1
Content-Type: application/json
{"name": "Ada"}POST says: here is data to act on. The body is the payload. The Content-Type header says how to read it.
curl -X POST -d '{"name":"Ada"}' https://api.example/users-X POST sets the method, -d sets the body. Two flags and you have built a POST by hand.
Each one is defined here on this site. Open the entry for the full definition and the other words it points at.