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semantic web

nounAlso: web of data, Linked Data, linked open data, LOD

In plain wordsAn effort to label data on the web in a standard, precise way so that programs, not only human readers, can tell what it means and connect facts drawn from many different sites.

  1. A vision, and a family of web standards, for publishing data on the World Wide Web with machine-interpretable meaning, so that software can find, combine and reason over information from many sources. Its standards, developed by the World Wide Web Consortium (W3C), form a layered stack: IRIs (web identifiers) to name things globally, RDFResource Description Framework, prop. n.: A web standard for writing facts as simple three-part statements — subject, relation, object — using web addresses as names, so that data from different sources can be merged automatically. to state facts as triples, RDF Schema and the Web Ontology LanguageWeb Ontology Language, prop. n.: A web standard language for writing ontologies — precise definitions of categories and their relationships — so that software can check them for contradictions and infer new facts. (OWL) to define vocabularies and ontologiesontology, n.: A carefully defined vocabulary for a subject such as medicine, spelling out each kind of thing, how kinds nest inside one another, and which connections between them are allowed. with description logicdescription logic, n.: A family of precise logical languages for defining categories and how they relate, such as 'a parent is a person with at least one child', designed so that a computer's reasoning about them always finishes. semantics, SPARQL to query and SHACL to validate data. The original vision of software agents arranging appointments across a fully semantic web was not realized at web scale, but the technologies succeeded in particular niches: Linked Open Data such as DBpedia and WikidataWikidata, prop. n.: A free, shared collection of facts about millions of things — people, places, books, chemicals — kept by volunteers in the Wikipedia family and laid out so programs can use it as easily as people., biomedical ontologies, enterprise knowledge graphsknowledge graph, n.: A huge web of facts stored as connections between things — 'Paris is the capital of France', 'Marie Curie won a Nobel Prize' — that computers can search, combine and reason over., and schema.org markup that search engines read from billions of web pages.

Origin

Tim Berners-Lee, inventor of the web, set out the 'Semantic Web' in the late 1990s, in W3C design notes such as his 'Semantic Web Road Map' (September 1998) and in his 1999 book Weaving the Web. The May 2001 Scientific American article by Berners-Lee, James Hendler and Ora Lassila popularized it, and the W3C issued RDF (1999), OWL (2004) and SPARQL (2008) as standards.

Usage note

Not to be confused with 'Web3', a later term for blockchain-based applications ('Web 3.0' has been used for both), or with semantic searchsemantic search, n.: Search that understands what you mean, not just the words you typed, so a search for 'cheap places to stay' also finds 'budget hotels'., retrieval by meaning using embeddings.

Related

See also
  • Resource Description FrameworkResource Description Framework, prop. n.: A web standard for writing facts as simple three-part statements — subject, relation, object — using web addresses as names, so that data from different sources can be merged automatically.
  • Web Ontology LanguageWeb Ontology Language, prop. n.: A web standard language for writing ontologies — precise definitions of categories and their relationships — so that software can check them for contradictions and infer new facts.
  • ontologyontology, n.: A carefully defined vocabulary for a subject such as medicine, spelling out each kind of thing, how kinds nest inside one another, and which connections between them are allowed.
  • knowledge graphknowledge graph, n.: A huge web of facts stored as connections between things — 'Paris is the capital of France', 'Marie Curie won a Nobel Prize' — that computers can search, combine and reason over.
  • description logicdescription logic, n.: A family of precise logical languages for defining categories and how they relate, such as 'a parent is a person with at least one child', designed so that a computer's reasoning about them always finishes.
  • WikidataWikidata, prop. n.: A free, shared collection of facts about millions of things — people, places, books, chemicals — kept by volunteers in the Wikipedia family and laid out so programs can use it as easily as people.
Contrast with
  • semantic searchsemantic search, n.: Search that understands what you mean, not just the words you typed, so a search for 'cheap places to stay' also finds 'budget hotels'.

Sources

  1. Berners-Lee, T., Hendler, J. & Lassila, O. (2001). The Semantic Web. Scientific American 284(5), 34–43.

Mentioned in

knowledge graphknowledge graph, n.: A huge web of facts stored as connections between things — 'Paris is the capital of France', 'Marie Curie won a Nobel Prize' — that computers can search, combine and reason over., ontologyontology, n.: A carefully defined vocabulary for a subject such as medicine, spelling out each kind of thing, how kinds nest inside one another, and which connections between them are allowed., semantic searchsemantic search, n.: Search that understands what you mean, not just the words you typed, so a search for 'cheap places to stay' also finds 'budget hotels'., WikidataWikidata, prop. n.: A free, shared collection of facts about millions of things — people, places, books, chemicals — kept by volunteers in the Wikipedia family and laid out so programs can use it as easily as people., closed-world assumptionclosed-world assumption, n.: The rule of treating whatever a system cannot confirm as false: if a library's catalog does not list a book, the library is assumed not to have it., description logicdescription logic, n.: A family of precise logical languages for defining categories and how they relate, such as 'a parent is a person with at least one child', designed so that a computer's reasoning about them always finishes., Resource Description FrameworkResource Description Framework, prop. n.: A web standard for writing facts as simple three-part statements — subject, relation, object — using web addresses as names, so that data from different sources can be merged automatically., Web Ontology LanguageWeb Ontology Language, prop. n.: A web standard language for writing ontologies — precise definitions of categories and their relationships — so that software can check them for contradictions and infer new facts.