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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
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<h3 class="category"><span class="ribbon"><a href="/standards/semanticweb/" title="Up to Semantic Web">Semantic Web <img src="/2008/site/images/header-link" alt="Header link" width="13" height="13" class="header-link" /></a></span></h3>
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<li><a href="/standards/semanticweb/query.html">Query</a></li>
<li><a href="/standards/semanticweb/ontology.html">Ontologies</a></li>
<li><a class="current">Data</a></li>
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<li><a href="/standards/">Standards</a> <span class="cr">»</span> </li>
<li><a href="/standards/semanticweb/">Semantic Web</a> <span class="cr">»</span> </li>
<li class="current">Data</li>
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<h1 class="title">
<img src="/2008/site/images/theme-web-semantics" alt="" />Linked Data</h1>
<ul class="w3c_toc">
<li class="toc_prefix">On this page → </li>
<li><a href="#summary">what is linked data</a>
<span class="bullet">• </span>
</li>
<li><a href="#uses">what is linked data used for</a>
<span class="bullet">• </span>
</li>
<li><a href="#examples">examples</a>
<span class="bullet">• </span>
</li>
<li><a href="#examples">learn more</a>
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<h2 id="summary">What is Linked Data?</h2>
<p>The Semantic Web is a Web of Data — of dates and titles
and part numbers and chemical properties and any other data one
might conceive of. The collection of Semantic Web technologies (RDF, OWL, SKOS, SPARQL, etc.) provides
an environment where application can <a href="query">query</a> that data, draw <a href="inference">inferences</a>
using <a href="ontology">vocabularies</a>, etc. </p>
<p>However, to make the Web of Data a reality, it is
important to have the huge amount of data on the Web available in a standard format, reachable and
manageable by Semantic Web tools. Furthermore, not only does the Semantic Web need access to
data, but <em>relationships among data</em> should be made available, too, to create
a <em>Web</em> of Data (as opposed to a sheer collection of datasets). This collection of
interrelated datasets on the Web can also be referred to as Linked Data.</p>
<p>To achieve and create Linked Data, technologies should be available for a common format (RDF),
to make either conversion or on-the-fly access to existing databases (relational, XML, HTML, etc). It is also important to be able to setup
<a href="query">query</a> endpoints to access that data more conveniently.
W3C provides a palette of technologies (RDF, GRDDL, POWDER, RDFa, the upcoming R2RML,
RIF, SPARQL) to get access to the data.
</p>
<h2 id="uses">What is Linked Data Used For?</h2>
<p>Linked Data lies at the heart of what Semantic Web is all about: large scale integration of, and
reasoning on, data on the Web. Almost all applications listed in, say
<a href="http://www.w3.org/2001/sw/sweo/public/UseCases/">collection of Semantic Web Case Studies
and Use Cases</a> are essentially based on the accessibility of, and integration of Linked Data at various
level of complexities. </p>
<h2 id="examples">Examples</h2>
<p>A typical case of a large Linked Dataset is <a href="http://dbpedia.org">DBPedia</a>,
which, essentially, makes the content of Wikipedia available in RDF. The importance of DBPedia is
not only that it includes Wikipedia data, but also that it
incorporates links to <em>other</em> datasets on the Web, e.g., to
<a href="http://www.geonames.org/">Geonames</a>. By providing those extra links
(in terms of RDF triples) applications may exploit the extra (and possibly more precise)
knowledge from other datasets when developing an application; by virtue of integrating facts from
several datasets, the application may provide a much better user experience.</p>
<h2 id="learnmore">Learn More</h2>
<p>
Tim Berners-Lee's <a href="http://www.w3.org/DesignIssues/LinkedData.html">note on Linked Data</a> gives a succinct description of the Linked Data principles.
The Semantic Web community also maintains a <a href="http://esw.w3.org/topic/SwBooks">list of books</a>
on a W3C Wiki page. Some of those books
are introductory in nature while others are conference proceedings or
textbook that address more advanced topics.
Details of <a href="http://www.w3.org/2007/11/Talks/Semantic_Web.html">recent and upcoming
Semantic Web related talks</a>, given by the <a href="http://www.w3.org/People/">W3C Staff</a>,
the <a href="http://www.w3.org/Consortium/Offices/">staff of the W3C Offices</a>,
and members of the W3C Working Groups are available separately; the slides
are usually publicly available. The
W3C also maintains a <a href="http://www.w3.org/2001/sw/sweo/public/UseCases/">collection of Semantic
Web Case Studies and Use Cases</a> that
show how Semantic Web technologies, including Linked Data, are used in
practice. </p>
<div id="pressreleases"></div>
<div id="recentpress"><!-- start generated recent press --><h2>Recent Press</h2>
<dl>
<dt>
<span class="press_date">9 January</span>
<br />
<a href="http://www.guadalinfo.es/index">Guadalinfo</a>
</dt>
<dd>
<a href="http://www.guadalinfo.es/node/444806">
“<cite>Día W3C en España</cite>”
</a>
</dd>
<dt>
<span class="press_date">8 January</span>
<br />
<a href="http://accesibilidadenlaweb.blogspot.com/">Accesibilidad en la Web</a>
</dt>
<dd>
<a href="http://accesibilidadenlaweb.blogspot.com/2012/01/dia-w3c-en-espana.html">
“<cite>Día W3C en España</cite>”
</a>
</dd>
<dt>
<span class="press_date">6 January</span>
<br />
<a href="http://www.stateofsearch.com/">State of Search</a>
</dt>
<dd>
<a href="http://www.stateofsearch.com/seo-2012-will-schema-be-a-factor/">
“<cite>SEO 2012 – Will Schema Be A Factor</cite>”
</a>
</dd>
<dt>
<span class="press_date">4 January</span>
<br />
<a href="http://www.lastampa.it/redazione/default.asp">La Stampa</a>
</dt>
<dd>
<a href="http://www.lastampa.it/_web/CMSTP/tmplrubriche/giornalisti/grubrica.asp?ID_blog=2&ID_articolo=1302">
“<cite>Tim Berners-Lee: "Tutti i nostri dati valgono oro"</cite>”
</a>
</dd>
</dl>
<!-- end generated recent press --></div>
<h2 id="specifications">Current Status of Specifications</h2>
<p>Learn more about the current status of specifications related
to:
</p>
<div id="w3c_techs_body"><ul class="show_items"><li>
<a href="/standards/techs/rdf">RDF</a>
</li><li>
<a href="/standards/techs/rdfbp">RDF Best Practices</a>
</li><li>
<a href="/standards/techs/rdfa">RDFa</a>
</li><li>
<a href="/standards/techs/rdfrel">RDF Relationship to Other Formats</a>
</li><li>
<a href="/standards/techs/grddl">GRDDL</a>
</li><li>
<a href="/standards/techs/powder">POWDER</a>
</li><li>
<a href="/standards/techs/sawsdl">Semantic Annotation for WSDL and XML Schema</a>
</li><li>
<a href="/standards/techs/provenance">Provenance</a>
</li></ul></div>
<p>These <a href="/Consortium/activities">W3C Groups</a> are
working on the related specifications:
</p>
<div id="w3c_groups"><ul class="show_items">
<li>
<a href="http://www.w3.org/html/wg/">HTML Working Group</a>
</li>
<li>
<a href="http://www.w3.org/2001/sw/rdb2rdf/">RDB2RDF Working Group</a>
</li>
<li>
<a href="http://www.w3.org/2010/02/rdfa/">RDF Web Applications Working Group</a>
</li>
<li>
<a href="http://www.w3.org/2011/rdf-wg/">RDF Working Group</a>
</li>
<li>
<a href="http://www.w3.org/2001/sw/interest/">Semantic Web Interest Group</a>
</li>
</ul></div>
</div>
<div class="unit size1on4 lastUnit w3c_rhs">
<div id="curstatusrhs">
<h2 class="h4 category">Current Status</h2>
<ul class="theme right-side">
<li>
<a href="/standards/techs/rdf">RDF</a>
</li>
<li>
<a href="/standards/techs/rdfbp">RDF Best Practices</a>
</li>
<li>
<a href="/standards/techs/rdfa">RDFa</a>
</li>
<li>
<a href="/standards/techs/rdfrel">RDF Relationship to Other Formats</a>
</li>
<li>
<a href="/standards/techs/grddl">GRDDL</a>
</li>
<li>
<a href="/standards/techs/powder">POWDER</a>
</li>
<li>
<a href="/standards/techs/sawsdl">Semantic Annotation for WSDL and XML Schema</a>
</li>
<li>
<a href="/standards/techs/provenance">Provenance</a>
</li>
</ul>
</div>
<div id="useitrhs">
<h2 class="h4 category">Use It</h2>
<ul class="theme right-list">
<li class="tutorials_link">
<a href="/2002/03/tutorials#semanticweb_data">Tutorials</a>
</li>
<li>Business Case</li>
<li>Software</li>
</ul>
</div>
<div id="validatorsrhs">
<h2 class="h4 category">Validators</h2>
<ul class="theme right-list">
<li>
<a title="RDF Validator" href="http://www.w3.org/RDF/Validator/">RDF</a>
</li>
</ul>
</div>
<div id="logosrhs">
<h2 class="h4 category">Logos</h2>
<ul class="theme right-list">
<li>
<a href="http://www.w3.org/2007/10/sw-logos.html#sw-rdf">RDF</a>
</li>
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