All things being described by ResourceDescriptionFramework expressions are called RDF resources. A resource may be a WikiPage. A resource may also be an object that is not directly accessible via the Web; e.g. a printed book. Resources are always named by UniformResourceIdentifier plus optional anchor ids.
See also: http://www.w3.org/TR/REC-rdf-syntax/#basic | ResourceDescriptionFramework | SemanticWikiWikiWeb | ...