Resource Description Framework
The Resource Description Framework (RDF) is a standard model for describing resources in the World Wide Web, and is considered the base technology of the Semantic Web. Resources may be any subject or entity, and are identified by a corresponding URI. Resources are typically described as triples, which consists of a subject, predicate and object:
Each part of the triple is itself a resource, which may also be linked to more resources through the triple syntax. In this manner RDF can facilitate easy exchange of resources and metadata about resources.
RDF is frequently expressed in XML. This syntax is defined by W3C and is referred to as RDF/XML.