The relashionship between a URI and a resource. A URI identify only one resource, it acts as a "virtual" delegate for that resource on the Web. This is different from the refersTo relashionships. This latter holds between Resources, and it's not functional. For example, http://www.example.com#me identifies only john, while john's homepage http://www.example.com/john.html refersTo me, the place where he works, his job, his personal interests, etc. If I want to describe John's characteristics e.g. his name, age, etc. on the Web, I will attach them to http://www.example.com#john. On the other hand, http://www.example.com/john.html identifies john's homepage, which is an information resource.