rdfRDF

rdfRDF, commonly written as the root element rdf:RDF in RDF/XML documents, is the container that represents an RDF graph in the XML serialization defined by the W3C RDF/XML syntax specification. The element appears once per document and may declare XML namespaces, most notably xmlns:rdf for the RDF vocabulary and additional prefixes for resources used in the graph.

In RDF/XML, the graph’s subjects are represented by rdf:Description elements, or by using an element with an rdf:about attribute to name a resource. Within a subject description, child elements whose qualified names denote predicates express the properties of that subject. The object of a property is provided as the content of the predicate element: it can be a literal (with optional datatype via rdf:datatype or a language tag via xml:lang), a resource identified by an rdf:resource attribute, or a nested rdf:Description describing a blank node.

RDF containers can be represented using RDF/XML constructs such as rdf:Seq, rdf:Bag, and rdf:Alt, with rdf:li used to denote items. Blank nodes may be expressed with rdf:nodeID or by providing a nested Description without a global identifier. RDF/XML also supports various constructs for representing language-tagged literals, typed literals, and nested resources within the graph.

RDF/XML is one of several serializations for RDF data. While it preserves the same underlying graph as formats like Turtle, N-Triples, or JSON-LD, RDF/XML tends to be verbose and less human-readable, which has influenced its adoption in various tools and systems. The rdf:RDF root thus plays a central role in translating RDF data between XML and the RDF model.