Representational State Transfer (REST) is a style of software architecture for distributed hypermedia systems such as the World Wide Web. A service is described as RESTful when it conforms to the tenets of REST. Although a full discussion of REST is outside the scope of this document, a RESTful Service has the following characteristics:
Data is modelled as a set of resources. Resources are identified by URLs.
A small set of operations are used to manipulate resources (for example, PUT, POST, GET, DELETE).
A resource can have multiple representations (for example, a blog might have a HTML representation and a RSS representation).
Services are stateless and since it is likely that the client wants to access related resources, these should be identified in the representation returned, typically by providing hypertext links.