The Semantic Web is the web of data which allows machines to understand about the meaning or semantics of information on the internet or World Wide Web.
When discussing the Semantic Web, it is prudent to note that we are in fact dealing with but one of several interrelated emerging technology domains: Web Services (providing distributed functionality). Grid Services (integrating distributed resources), and the Semantic Web (mapping and managing the resources). To map World Wide Web resources more accurately, computational agents need machine-readable explanations of the content and capabilities of the Web accessible resources and descriptions have to be besides to the human-readable editions or format of that data, matching however should not be supplanting.
The requirement to be machine-readable is non-negotiable, because in future - in fact, practically already now - almost all software (and devices) will be innately Web-aware. Leveraging autonomic-computing technology enables agents and empowered devices to display independent activity and initiative, thus requiring less hands-on management by users. Already, an important expectation about software is that even 'dumb' applications can deal with basic Web connectivity in ways appropriate to their primary function.
The architectural models and fundamental terms used in the discussions of the Semantic Web. From Model to Reality starts with a summary of the conceptual models for the Semantic Web, before delving further into detailed terms.