The relationship between Web services and stateful resources is defined in [WS-Resource]. This relationship is described as the implied resource pattern. In the implied resource pattern, messages to a Web service may include a component that identifies a stateful resource to be used in the execution of the message. We refer to the composition of a stateful resource and a Web service under the implied resource pattern as a WS�18 Resource.
This document standardizes the means by which the definition of the properties of a WS�20 Resource may be declared as part of a Web service interface. The declaration of the WS�21 Resource’s properties represents a projection of or a view on the WS-Resource’s state.
This projection is defined in terms of a resource properties document. This resource properties document serves to define a basis for access to the resource properties through Web service interfaces.
This specification also defines a standard set of message exchanges that allow a requestor to query or update the property values of the WS-Resource. The set of properties defined in the resource properties document associated with the service interface defines the constraints on the valid contents of these message exchanges.