Chapter 4 - Semantic Web application architecture

Abstract

The components described in this chapter—RDF parsers, serializers, stores, and query engines—are the components of a system that includes semantic models. The information represented in RDF is the building block that goes into making and using a semantic model. The model is represented in RDF. The semantic modeling languages of the W3C, RDFS, and OWL are built entirely in RDF, and they can be federated just like any other RDF data. As data expressed in RDF, semantic models are housed in the RDF store, along with all other data. Semantic models also include meta-data--data that help to organize other data. When the information is federated from multiple sources, the RDF data model allows one to represent all the data in a single, uniform way. A semantic model acts as a sort of glue between disparate, federated data sources, so they can be described as how they fit together. Anyone can contribute to the definition and mapping between information sources. In this way, not only can a federated, RDF-based, semantic application get its information from multiple sources, but it can even get the instructions on how to combine information from multiple sources. In this way, the Semantic Web really is a web of meaning, with multiple sources describing what the information on the Web means.