OWL DL

OWL-DL is much more expressive than OWL-Lite and is based on Description Logics (hence the suffix DL). Description Logics are a decidable fragment of First Order Logic2 and are therefore amenable to automated reasoning. It is therefore possible to automatically compute the classification hierarchy and check for inconsistencies in an ontology that conforms to OWL-DL.

An owl class (owl:class) is defined as subclass of rdfs class (rdfs:class); not all classes of RDF document can be an instances or subclasses of an owl class (owl:class); as a result, a valid rdf document cannot be considered as a valid OWL Lite or DL document. It is different from OWL Lite in lower level language details and constraints.