The terms used to represent and describe an area of knowledge is called as ontology. For applications that need to merge information from or search across diverse communities ontologies are critical. Although DTDs , XML and XML Schemas are enough for exchanging data between parties who have beforehand agreed to the definitions. Due to their lack of semantics the machines deny performing this task with new XML vocabularies.
The vision for the future of the web is Semantic web in which explicit meaning is given to information, making
The future of Web languages seems to be the Semantic Web, and OWL is one of its activities. Now a question arises: What does OWL provide that XML and XML Schema don't? The answer is outlined below.
1. XML provides a syntax for structured documents, but doesn't define semantic constraints on the meaning of the documents.
2. XML Schema is a language for restricting the structure of XML documents.
3. RDF is a data model for objects ("resources") and relations between them; it provides simple semantics for this data model, and these data models can be
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Resource Description Framework (RDF). W3C Main Page
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RDF FAQ Document, from W3C
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W3C Metadata Activity Statement. Explains W3C's plans for RDF and metadata in detail. Work on Metadata is part of W3C's Technology and Society Domain.
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RDF Interest Group. "The RDF Interest Group was established in August 1999 as an open forum for W3C Members and non-Members to discuss issues relating to W3C's Resource Description Framework." See the RDF IG Charter and the archives of the RDF-Interest mailing list
GILS subset of the Basic Semantics Register (with stylesheet)
This RDF schema contains GILS schema elements as registered in the ISO Basic Semantics Register (BSR). It defines a hierarchy of RDF Classes rooted to the BSR concept "InformationResource" (RDF Classes are roughly equivalent to BSR Semantic Components). The RDF schema also defines for each GILS element an RDF Property (RDF Properties are roughly equivalent to BSR Semantic Units).
English tags in SGML/XML (with stylesheet)
This RDF schema has SGML/XML element tags in English, expressed as
The formal specification of knowledge, which is also known as knowledge representation, is not new. Long before the Semantic Web knowledge representation has been part of several studies. Starting in the seventies AI-scientists startet to work on predicate logics for the formal specification of knowledge. Later on knowledge representation with description logics, which are a subtype of predicate logics. Description logics powress is restriced compared to predicate logics but allows efficient reasoning.
In 2001 Tim Berners-Lee and others published an
RSS/XML