The Semantic Web is an extension of the World Wide Web that aims to make web content more easily discoverable and understandable by machines. It involves adding metadata to web pages in order to enable machines to better understand how information is related and to provide more relevant search results. The goal of the Semantic Web is to enable a more intelligent web where information can be automatically integrated and interpreted in meaningful ways. Key technologies used in the Semantic Web include RDF (Resource Description Framework), OWL (Web Ontology Language), and SPARQL (SPARQL Protocol and RDF Query Language).