Ontologies are formalized vocabularies of terms, often covering a specific
domain and shared by a community of users. They specify definitions of
terms by describing their relationships to other terms in the ontology in
order to make Web content more machine-readable. An OWL 2 profile is a
reduced version of OWL 2 that trades some expressive power for reasoning
efficiency. For this reason, users may wish to request an ontology in a
specific OWL profile, e.g. OWL 2 EL or OWL 2 QL.