What HTTP status codes are used when working with REST API?

Standard HTTP status codes are used when working with REST APIs to help the client understand the result of a request. The main ones are:

• 200 OK — the request was successful, and the server returns the requested data.
• 201 Created — the resource was successfully created (e.g., after a POST request).
• 204 No Content — the request was successful, but there is no response body (e.g., after a successful DELETE).
• 400 Bad Request — the request was invalid, a client-side error (e.g., incorrect data format).
• 401 Unauthorized — authentication is required or has failed.
• 403 Forbidden — access is denied even if authentication was successful.
• 404 Not Found — the requested resource was not found.
• 409 Conflict — there was a conflict when executing the request (e.g., trying to create a duplicate).
• 500 Internal Server Error — an error occurred on the server side.

These codes help standardize interactions and simplify response handling on the client side.