In
information science, an
upper ontology (also known as a
top-level ontology or
foundation ontology) is an
ontology (in the sense used in information science) which describes very general concepts that are the same across all
knowledge domains. An important function of an upper ontology is to support broad
semantic interoperability among a large number of domain-specific ontologies which are accessible ranking "under" this upper ontology. As the rank
metaphor suggests, it is usually a
hierarchy of entities and associated rules (both
theorems and
regulations) that attempts to describe those general entities that do not belong to a specific problem domain.