The characteristic that sets data ontologies apart from other data models, such as relational models, is that relationships are named. For example, instead of saying that there is an entity shop related to an entity book, our data model states that the shop sells the book. In other words, the relationship between these two pieces of data, shop and book is itself a piece of data: sells.
This is usually absent from more conventional relational data models, where entities such as shop and book are often related by an ID reference which tells us nothing about what the relationship is.
This feature of ontologies — naming relationships — is what gives them their power when we apply them to sources in the arts, humanities and social sciences. It makes the relationships between data more semantically meaningful, and this is needed in order to be able to describe a complex knowledge domain accurately. For example, if a person called John is related to a person called Jane, it is usually important to know whether that relationship is as a parent, sibling, spouse, or friend.
URL for this page
https://www.dhi.ac.uk/books/ontology-guide/naming-relationships