RDF/XML is a syntax, defined by the W3C , to express (i.e. serialize) an RDF graph as an XML document. According to the W3C, "RDF/XML is the normative syntax for writing RDF". RDF (Resource Description Framework) is the data model used to represent semantic web resources.
RDF/XML is seen by some as the machine readable form of RDF with Notation 3 as a more human-readable form. Joshua Tauberer, for instance, said that RDF/XML "may have a more intuitive feel but tends to obscure the underlying graph".