The Web Ontology Language (OWL) is a semantic web language designed to represent rich and complex knowledge about things, groups of things, and relations between them. It allows users to create ontologies, which are formal representations of a set of concepts within a domain and the relationships between those concepts. OWL is built on top of Resource Description Framework (RDF) and provides more vocabulary for describing properties and classes. OWL supports reasoning about the properties of classes and instances, enabling automated systems to infer new knowledge. It is widely used in various fields, including artificial intelligence, biomedical research, and information retrieval, to enhance data interoperability and facilitate better data sharing across different systems.