Overview of content related to 'xhtml' http://www.ariadne.ac.uk/taxonomy/term/103/all?article-type=&term=&organisation=&project=&author=henry%20s.%20thompson&issue= RSS feed with Ariadne content related to specified tag en What Is a URI and Why Does It Matter? http://www.ariadne.ac.uk/issue65/thompson-hs <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue65/thompson-hs#author1">Henry S. Thompson</a> describes how recent developments in Web technology have affected the relationship between URI and resource representation and the related consequences.</p> </div> </div> </div> <p>URI stands for Uniform Resource Identifier, the official name for those things you see all the time on the Web that begin <font face="Courier New, Courier, monospace">'http:'</font> or <font face="Courier New, Courier, monospace">'mailto:'</font>, for example <span class="style1">http://<em>www.w3.org</em>/</span>, which is the URI for the home page of the World Wide Web Consortium [<a href="#1">1</a>]. (These things were called URLs (Uniform Resource Locators) in the early days of the Web, and the change from URL to URI is either hugely significant or completely irrelevant, depending on who is talking—I have nothing to say about this issue in this article. If you have never heard of URIs (or IRIs, the even more recent fully internationalised version), but are familiar with URLs, just think 'URL' whenever you see 'URI' below.)</p> <p>Historically, URIs were mostly seen as simply the way you accessed Web pages. These pages were hand-authored, relatively stable and simply shipped out on demand. More and more often that is no longer the case; in at least three different ways:</p> <ul> <li>Web pages for reading have been complemented by pictures for viewing, videos for watching and music for listening;</li> <li>The Web is now more than a conduit for information, it is a means to a variety of ends; we use it to <em>do</em> things: purchase goods and services, contribute to forums, play games;</li> <li>The things we access on the Web are often not hand-authored or stable, but are automatically synthesised from 'deeper' data sources on demand. Furthermore, that synthesis is increasingly influenced by aspects of the way we initiate the access.</li> </ul> <p>It is against this background that I think it is worth exploring with some care what URIs were meant to be, and how they are being used in practice. In particular, I want to look at what is to be gained from a better understanding of how other kinds of identifiers work.</p> <h2 id="The_Official_Version">The Official Version</h2> <p>Insofar as there are definitive documents about all this, they all agree that URIs are, as the third initial says, <strong>identifiers</strong>, that is, names. They identify <strong>resources</strong>, and often (although not always) allow you to access <strong>representations</strong> of those resources. (Words in <strong>bold</strong> are used as technical terms—their ordinary language meaning is in many cases likely to be more confusing than helpful.)</p> <p>'Resource' names a role in a story, not an intrinsically distinguishable subset of things, just as 'referent' does in ordinary language. Things are resources because someone created a URI to identify them, not because they have some particular properties in and of themselves.</p> <p>'Representation' names a pair: a character sequence and a media type. The <strong>media type</strong> specifies how the character string should be interpreted. For example JPG or HTML or MP3 would be likely media types for representations of an image of an apple, a news report about an orchard or a recording of a Beatles song, respectively.</p> <p></p><p><a href="http://www.ariadne.ac.uk/issue65/thompson-hs" target="_blank">read more</a></p> issue65 feature article henry s. thompson apple google ietf university of edinburgh w3c wikipedia aggregation ajax algorithm browser cataloguing cookie data framework gif google maps html hypertext identifier javascript jpg metadata mp3 png rfc search technology semantic web uri url web 2.0 web app xhtml Fri, 29 Oct 2010 23:00:00 +0000 editor 1589 at http://www.ariadne.ac.uk The W3C Technical Architecture Group http://www.ariadne.ac.uk/issue51/thompson <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue51/thompson#author1">Henry S. Thompson</a> introduces the W3C Technical Architecture Group and its work.</p> </div> </div> </div> <p><a href="http://www.ariadne.ac.uk/issue51/thompson" target="_blank">read more</a></p> issue51 feature article henry s. thompson google ibm ietf massachusetts institute of technology oasis sun microsystems university of cambridge university of edinburgh w3c archives cataloguing doi html identifier metadata namespace passwords rdf research schema search technology semantic web sgml uri urn xhtml xml xml schema Sun, 29 Apr 2007 23:00:00 +0000 editor 1306 at http://www.ariadne.ac.uk