The Semantic Web consists of many RDF graphs nameable by URIs. This paper extends the syntax and semantics of RDF to cover such named graphs. This enables RDF statements that describe graphs, which is beneficial in many Semantic Web application areas. Named graphs are given an abstract syntax, a formal semantics, an XML syntax, and a syntax based on N3. SPARQL is a query language applicable to named graphs. A specific application area discussed in detail is that of describing provenance information. This paper provides a formally defined framework suited to being a foundation for the Semantic Web trust layer.
