An ontology is a model that describes types of things that exist in a knowledge domain and the types of relationships between them.

An ontology is typically used to describe a particular domain of interest, for example a business. There are some attempts at creating generic ontologies, but these tend to be very large and complex.

The ontology describes:

  1. The types of things that will exist in the knowledge domain e.g. Person, Product, Company.
  2. The properties different type instances may have e.g. Date of Birth, Social Security Number.
  3. The types of relationships that can exist between different entities e.g. Person Works For Company, Person Is Expert In Product.