Ontology (noun)

1. The branch of metaphysics concerned with the nature of being, existence, and reality.
2. A particular theory or conception of the nature of being, existence, and reality.
3. In computer science, the study of the nature and categorization of objects and concepts within a specific domain or system.

Origin:

The term 'ontology' originated from the greek word 'ontos' meaning 'being' and 'logos' meaning 'study of', and was first used in metaphysics and philosophy to describe the study of the nature of being, existence, and reality.

Examples:

1. The philosopher's ontology was based on the belief that the universe was made up of both matter and spirit.
2. The ontology of the ancient Greeks was dominated by the concept of the polis, or city-state.
3. The ontology of the modern world is based on the idea of individualism and the pursuit of personal happiness.
4. The ontology of the computer system was designed to categorize objects based on their properties and relationships.
5. The ontology of the knowledge domain was used to develop a taxonomy of concepts and categories.