Resource Description Language RDF & RDF Schema
The Resource Description Framework (RDF) is a language for representing information about resources in the World Wide Web [304, 361] and has become a quite popular Semantic Web representation formalism. It is particularly intended for representing metadata about Web resources, such as the title and author of a Web page. However, by generalizing the concept of a “Web resource,” RDF can also be used to represent information about things that can be identified on the Web, even when they cannot be directly retrieved on the Web. For our purposes we can think of it as anything we can identify.