" It is no accident that in the field of philosophy ontology is the study of reality, existence and coming into being. In the fields of information retrieval (semantic search) and computing, ontology is the naming of the types, interrelationships and properties of the entities that exist (in reality or conceptually) and which define a particular domain of knowledge or expertise. "

― David Amerland , SEO Help: 20 Semantic Search Steps that Will Help Your Business Grow