Abstract

The “semantic web (SW)” is a vision of a web of linked data, allowing querying, integration, and sharing of data from distributed sources in heterogeneous formats, using ontologies to provide an associated and explicit semantic interpretation. This entry describes the series of layered formalisms and standards that underlie this vision, and chronicles their historical and ongoing development. A number of applications, scientific and otherwise, academic and commercial, are reviewed. The SW has often been a controversial enterprise, and some of the controversies are reviewed, and misconceptions defused.