Rdf Primer / quote 10 of 55
Anything with a URI reference is a resource
Because of this generality, RDF uses URIs as the basis of its mechanism for identifying the subjects, predicates, and objects in statements. To be more precise, RDF uses URI references [URIS]. A URI reference (or URIref) is a URI, together with an optional fragment identifier at the end. For example, the URI reference http://www.example.org/index.html#section2 consists of the URI http://www.example.org/index.html and (separated by the "#" character) the fragment identifier Section2. RDF URIrefs can contain Unicode [UNICODE] characters (see [RDF-CONCEPTS]), allowing many languages to be reflected in URIrefs. RDF defines a resource as anything that is identifiable by a URI reference, so using URIrefs allows RDF to describe practically anything, and to state relationships between such things as well.