Representational State Transfer

Representational State Transfer (REST) is a software architecture style for building scalable web services. REST gives a coordinated set of constraints to the design of components in a distributed hypermedia system that can lead to a more performant and maintainable architecture.

REST stands for Representational State Transfer. (It is sometimes spelled "ReST".) It relies on a stateless, client-server, cacheable communications protocol -- and in virtually all cases, the HTTP protocol is used.

REST is an architecture style for designing networked applications. The idea is that, rather than using complex mechanisms such as CORBA, RPC or SOAP to connect between machines, simple HTTP is used to make calls between machines.

REST is a lightweight alternative to mechanisms like RPC (Remote Procedure Calls) and Web Services (SOAP, WSDL, et al.).

RESTful programming is about:

1.Resources being identified by a persistent identifier: URIs are the found everywhere/ubiquitous choice of identifier these days.

2.Resources being manipulated using a common set of verbs: HTTP methods are the commonly seen case - the venerable Create, Retrieve, Update, Delete becomes POST, GET, PUT, and DELETE.

3.The actual representation retrieved for a resource is dependent on the request and not the identifier: use HTTP Accept headers to control whether you want XML, HTTP, or even a Java Object representing the resource.

4.Maintaining the state in the object and representing the state in the representation.

5.Representing the relationships between resources in the representation of the resource: the links between objects are embedded directly in the representation.

6.Resource representations describe how the representation can be used and under what circumstances it should be discarded/refetched in a consistent manner: usage of HTTP Cache-Control headers.