The RESTful API refers to an interface that is based on the REST architectural style and separates the implementation of web services on a server from the user interface implemented by a client. This separation provides good portability for a web service so it can serve different clients across multiple platforms, and offers great user experience for the client so it can keep the native design of the client platform and provides a uniform look and feel to the users.
In general, the REST architecture assumes a stateless server, hence the session state is kept entirely on the client side. Each HTTP request the client makes must contain all information the server needs to understand the request and provide an expected response. In Chapter 9, Adding Authentication, you've already learned how to maintain the session of a successful login via...