Ontology is a branch of philosophy that studies the nature of being, existence, and reality. It explores questions about what entities exist and how they can be categorized and related to one another. Ontology helps in understanding the fundamental categories of things, such as objects, properties, and events. In computer science and information science, ontology refers to a structured framework that organizes information. It defines the relationships between different concepts within a specific domain, enabling better data sharing and retrieval. For example, an ontology in artificial intelligence might categorize various types of data and their interconnections.