REST is an approach to providing web-based API that is based on standard HTML conventions. It identifies the data on which the API acts, known as the resources, by URL. It uses standard HTML methods, GET, PUT, DELETE and POST, to specify actions on the resources. It uses standard HTTP response codes to signal success and failure.
The REST approach supersedes earlier web service interfaces documented in Web service interface and Using JSON in web service calls. The REST approach is more flexible, more standard and provides more features than the earlier interface approaches and should be used for new solutions.