An ontology is a description of data structure–of classes, properties, and relationships in a domain of knowledge. It is meant to serve as a basis for instances of knowledge graphs, ensuring data consistency and understanding of the data model. Some widely adopted ontologies, such as RDF, RDFS or SKOS are used as tools for standardisation and increasing compatibility between different graphs.
Ontologies are usually written in OWL (Web Ontology Language)
A very simple example of an ontology is as follows:
Colours
– haveSubClass – Warm Colours
– haveInstance – Yellow