МСУРечь о REST vs SOAP. У REST нету схемы, у SOAP есть. Вот и всё отличие.REST - это архитектурный стиль. Правильней сравнивать его с RPC.


http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#relwwwrest 3.1.3 Relationship to the World Wide Web and REST Architectures

The World Wide Web operates as a networked information system that imposes several constraints: Agents identify objects in the system, called resources, with Uniform Resource Identifiers (URIs). Agents represent, describe, and communicate resource state via representations of the resource in a variety of widely-understood data formats (e.g. XML, HTML, CSS, JPEG, PNG). Agents exchange representations via protocols that use URIs to identify and directly or indirectly address the agents and resources. [Web Arch]

An even more constrained architectural style for reliable Web applications known as Representation State Transfer (REST) has been proposed by Roy Fielding and has inspired both the W3C Technical Architecture Group's architecture document [Web Arch] and many who see it as a model for how to build Web services [Fielding]. The REST Web is the subset of the WWW (based on HTTP) in which agents provide uniform interface semantics -- essentially create, retrieve, update and delete -- rather than arbitrary or application-specific interfaces, and manipulate resources only by the exchange of representations. Furthermore, the REST interactions are "stateless" in the sense that the meaning of a message does not depend on the state of the conversation.

We can identify two major classes of Web services :

- REST-compliant Web services, in which the primary purpose of the service is to manipulate XML representations of Web resources using a uniform set of "stateless" operations; and
- arbitrary Web services, in which the service may expose an arbitrary set of operations.

Both classes of Web services use URIs to identify resources and use Web protocols (such as HTTP and SOAP 1.2) and XML data formats for messaging. ( It should be noted that SOAP 1.2 can be used in a manner consistent with REST. However, SOAP 1.2 can also be used in a manner that is not consistent with REST.)

Ну, и напоследок небольшой разрыв шаблона - описание REST-сервиса на WSDL.