On the one hand, ontology is a philosophical discipline that deals with classifying concepts of the world into category systems that are as meaningful as possible. On the other hand, in computer science, concrete category systems of this kind, for example consisting of concepts and relations for algorithmic use, are called ontologies as well.

ETSI GR ENI 004 explicit specification of a conceptualization

NOTE 1: As defined in [i.14].

NOTE 2: This definition is the basis for definitions in OneM2M and SmartM2M.

language, consisting of a vocabulary and a set of primitives, that enable the semantic characteristics of a domain to be modelled