What status codes can you name and describe their meanings?

In protocols, especially HTTP, there are status codes that inform the client about the result of the request. Main groups and examples of codes:

• 1xx (Informational): The request has been received, and processing continues.

  • 100 Continue — the client can continue sending the request.

• 2xx (Success): The request was successfully processed.

  • 200 OK — the request was successful.
  • 201 Created — the resource was successfully created.

• 3xx (Redirection): Additional action by the client is required.

  • 301 Moved Permanently — the resource has been permanently moved.
  • 302 Found — temporary redirection.

• 4xx (Client errors): Errors on the client side.

  • 400 Bad Request — invalid request.
  • 401 Unauthorized — authentication is required.
  • 403 Forbidden — access is denied.
  • 404 Not Found — resource not found.

• 5xx (Server errors): Errors on the server side.

  • 500 Internal Server Error — internal server error.
  • 503 Service Unavailable — service is unavailable.

These codes help understand what happened with the request and how the client should respond.