Ontology

Natural & Formal Sciences Dictionary
A formal, explicit specification of concepts, classes, relationships, properties, and axioms within a domain that enables shared understanding, reasoning, and interoperability across systems and agents.

Ontology

Humanities & Arts Dictionary
A structured inventory of categories, types, and interrelations that specifies which kinds of entities are posited to exist and how they are related within a given metaphysical, theoretical, or representational account.