RDF Schema (RDFS)
RDF Schema (RDFS) is an extension to RDF.
RDF Schema and Application Classes
RDF describes resources with classes, properties, and values.
In addition, RDF also need a way to define application-specific classes and
properties. Application-specific classes and properties must be defined using
extensions to RDF
One such extension is RDF Schema.
RDF Schema (RDFS)
RDF Schema does not provide actual application-specific classes and
properties.
Instead RDF Schema provides the framework to describe application-specific
classes and properties
Classes in RDF Schema is much like classes in object oriented programming
languages. This allows resources to be defined as instances of classes, and
subclasses of classes.
RDFS Example
The following example demonstrates some of the RDFS facilities:
<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf= "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xml:base= "http://www.animals.fake/animals#">
<rdf:Description rdf:ID="animal">
<rdf:type
rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
</rdf:Description>
<rdf:Description rdf:ID="horse">
<rdf:type
rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
<rdfs:subClassOf rdf:resource="#animal"/>
</rdf:Description>
</rdf:RDF>
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In the example above, the resource "horse" is a subclass of the
class "animal".
Example Abbreviated
Since an RDFS class is an RDF resource we can abbreviate the example above by
using rdfs:Class instead of rdf:Description, and drop the rdf:type information:
<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf= "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xml:base= "http://www.animals.fake/animals#">
<rdfs:Class rdf:ID="animal" />
<rdfs:Class rdf:ID="horse">
<rdfs:subClassOf rdf:resource="#animal"/>
</rdfs:Class>
</rdf:RDF>
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That's it!
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