The Semantic Web Languages

The Semantic Web is basically an extension of the Web and of the Web-enabling database and Internet technology, and, as a consequence, the Semantic Web methodologies, representation mechanisms and logics strongly rely on those developed in databases. This is the motivation for many attempts to, more or less loosely, merge the two worlds like, for instance, the various proposals to use relational technology for storing web data or the use of ontologies for data integration. This article comes second in this book, after an article on data management, in order to first complete the picture with the description of the languages that can be used to represent information on the Semantic Web, and then highlight a few fundamental differences which make the database and Semantic Web paradigms complementary but somehow difficult to integrate.