The Web Ontology Language (OWL maybe because some non English speaker must have mixed the letters…) exists in three different versions :

• OWL Lite expresses constraints on and properties of an RDF schema, such as transitivity (if R1 > P1 > R2 and R2 > P2 > R3 then R1 > P3 > R3), and simple min and max cardinality properties of an RDF property (the values of theses cardinality properties can be 0, 1 or illimited).
• OWL DL expresses « first order descriptive logic » constraints on medata (such as if R1 > P1 > R2 then R1 > P2 > R3), this is much broader as OWL Lite
• OWL Full enables the specification of generic inference engines but it is still seen by some as a curiosity artefact for researchers

This is my very limited understand of the OWL topic. Please someone correct me if I am wrong (you can do it in French if you want !) !