Ontology is the study or analysis of the fundamental concepts and relationships in a domain.
OWL2 is a language and formalism for representing heterogenous conceptual domains, for reasoning about properties of the domains, and for simplifying the model-to-model transformation workflow required for projecting information from one domain into another 1) 2). OWL2 allows the separation of ontology from semantics of SysML and allows flexibility to change the mapping of domain concepts (as stereotypes) into SysML entities without impacting the underlying concepts.