describe groups of same kind resources 
(classes) and the inclusiveness among these groups. RDFS provides the minimal 
set for describing concepts for ontology. The vocabulary contains rdfs:Resource 
and rdfs:Class, which provide the classification notion together with the 
property rdf:type, and the subsumption notion of classification with the 
property rdfs:subClassOf. These semantics of RDFS is similar to the CLOS 
perspective, namely rdf:type to instance-class relation and rdfs:subClassOf to 
subclass-