HTTP Status Codes

1xx: Informational - Request received / processing.

2xx: Success - Successfully Received, understood and accepted.

3xx: Redirect - Further action must be taken / redirect.

4xx: Client Error - Request does not have what it needs.

5xx: Server Error - Server failed to fulfil an apparent valid request.

200 - OK
201 - OK Created
301 - Moved to new URL
304 - Not modified (Cached version)
400 - Bad request
401 - Unauthorized
404 - Not found
500 - Internal server error