ABSTRACT
The Resource Description Framework,[1] or RDF, is a knowledge representation language for the Semantic Web,[2,3] and is used to express knowledge about things both on and off the Web; RDF can be used to write metadata about web pages and to describe real-world objects with equal facility. RDF is a key language in the technical architecture of the Semantic Web, being both a format for describing instance data, and the foundation for the vocabulary definition languages RDF Schema[4] and OWL.[5]
The Semantic Web is a development of the World Wide Web that aims to provide an infrastructure for machine-understandable information on the Web. By expressing information in a form that makes the meaning, or semantics, accessible to machines, the goal of the Semantic Web is to create a next-generation Web in which information can be mediated by software agents on behalf of and without intervention from their users. At present, information on the World Wide Web is predominantly textual and requires human understanding to interpret it; the meaning of such natural language information must be made explicit if a machine is to be able to make sense of it. In artificial intelligence, the long-standing discipline of knowledge representation has developed a variety of approaches for expressing information to facilitate reasoning; these knowledge representation languages are of varying degrees of complexity and expressivity, but they share the common feature
Introduction .................................................................................................................................... 659 The Triple Model ...........................................................................................................................660 Comparing XML and RDF............................................................................................................ 661 Feature Summary........................................................................................................................... 662
Classes....................................................................................................................................... 662 Properties...................................................................................................................................663 Containers and Collections.......................................................................................................663 Reification.................................................................................................................................664 Ancillary Properties..................................................................................................................665
