RDF schema
| Status | Published |
|---|---|
| Year started | 1998 |
| Editors | Dan Brickley, Ramanathan V. Guha |
| Base standards | RDF |
| Related standards | OWL |
| Domain | Semantic Web |
| Abbreviation | RDFS |
| Website | RDF Schema |
RDF Schema (Resource Description Framework Schema, variously abbreviated as RDFS, RDF(S), RDF-S, or RDF/S) is a set of classes with certain properties using the RDF extensible knowledge representation data model, providing basic elements for the description of ontologies, otherwise called RDF vocabularies, intended to structure RDF resources. These resources can be saved in a triplestore to reach them with the query language SPARQL.
The first version was published by the World-Wide Web Consortium (W3C) in April 1998, and the finalW3C recommendation was released in February 2004. Many RDFS components are included in the more expressive Web Ontology Language (OWL).
RDFS constructs are the RDFS classes, associated properties and utility properties built on the limited vocabulary of RDF.
A typical example of an rdfs:Class is foaf:Person in the Friend of a Friend (FOAF) vocabulary. An instance of foaf:Person is a resource that is linked to the class foaf:Person using the rdf:type property, such as in the following formal expression of the natural-language sentence : 'John is a Person'.
ex:John rdf:type foaf:Person
The definition of rdfs:Class is recursive: rdfs:Class is the class of classes, and so it is an instance of itself.
rdfs:Class rdf:type rdfs:Class
The other classes described by the RDF and RDFS specifications are:
Properties are instances of the class rdf:Property and describe a relation between subject resources and object resources. When used as such a property is a (see also RDF: reification).
For example, the following declarations are used to express that the property ex:employer relates a subject, which is of type foaf:Person, to an object, which is of type foaf:Organization:
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