HTTP status codes: what do 401, 403, 500, 200, 201 mean?

HTTP status codes:

• 200 OK — The request was successful, and the server returned the requested data.
• 201 Created — The request was successful, and a new resource was created as a result (e.g., in a POST request).
• 401 Unauthorized — Unauthorized access. The client did not provide valid credentials or did not authenticate.
• 403 Forbidden — Access is denied. The client is authenticated but does not have permission to access the resource.
• 500 Internal Server Error — An internal server error occurred. An unexpected error happened while processing the request.

These codes help the client understand the result of the request and take appropriate actions.