HTTP Responses will always include an HTTP Status Code. The Status Code is used to convey the result of the HTTP Request.
The status codes are divided into five categories:
100s – Informational – Communicates transfer protocol-level information
200s – Success – Indicates that the client’s request was successfully accepted.
300s – Redirection – Indicates that the client must take additional action in order to complete the request.
400s – Client Error – Indicates a client error. This likely to be an error with the format of the HTTP Request or the data payload.
500s – Server Error – Indicates an internal error with the server when the request was processed.
HTTP Responses are cacheable which means that the response is stored by the REST Service in order to provide reduced response times.