What is the key difference between GET and POST requests? How do they differ technically?

GET and POST are two main HTTP methods used for client-server interaction.

Key differences:

• GET:

  • Used to retrieve data from the server.
  • Parameters are passed in the URL (query string).
  • Requests can be cached and stored in the browser history.
  • Idempotent — repeated requests should not change the server state.

• POST:

  • Used to send data to the server, for example, to create or update resources.
  • Data is sent in the request body.
  • Not cached and not stored in browser history.
  • Can change the server state and is not idempotent.

Example:

GET /users?id=123 HTTP/1.1
Host: example.com

POST /users HTTP/1.1
Host: example.com
Content-Type: application/json

{"name": "Ivan", "age": 30}

Thus, GET is for requesting data, POST is for sending data and changing the server state.