Mae West said, "When choosing between two evils, I always like to try the one I've never tried before." But, sometimes, when choosing between two equally appealing options, the best policy is to take both. WS-ResourceFramework and WS-Transfer, two new specifications for accessing XML representations of resources through Web Services have been announced. Although it's not uncommon to find competing specifications and standards in the world of Web Services, this time we shouldn't be forced to make an exclusive choice because WS-ResourceFramework and WS-Transfer can serve complimentary roles.
What do we mean by resource representation?
It's often considered to be the representation of the state of a resource - state being one or more characteristics, or properties, associated with a resource. For example, if a customer record in a CRM database is the actual resource, its representation may be an XML document transferred over the network or the information returned as part of a SQL query. Either the XML document or the query result can be viewed as representations of the actual resource - the customer record. The set of information residing in the database can be viewed as the state of that customer record.
Web-centric folks sometimes draw additional distinctions between the representation and the resource itself. For example, the World Wide Web Consortium's (W3C) Technical Architecture Group (TAG) has noted more precisely that an XML document can represent a particular state of a resource at a particular time [http://w3.org/TR/2004/REC-webarch-20041215/]. So, while it's important to understand that there may be a difference between saying "access to the resource" and saying "access to the representation of the resource," it's certainly understandable that people are quite casual about the difference in day-to-day conversations.
