URI Reference

Jump to: navigation, search

A URI Reference is a character string used to identify a name of a web resource

  • Example(s):
    • http://en.wikipedia.org/wiki/URI#Examples_of_URI_references ("http" specifies the 'scheme' name, "en.wikipedia.org" is the 'authority', "/wiki/URI" the 'path' pointing to this article, and "#Examples_of_URI_references" is a 'fragment' pointing to this section.)
    • http://example.org/absolute/URI/with/absolute/path/to/resource.txt
    • //example.org/scheme-relative/URI/with/absolute/path/to/resource.txt
    • /relative/URI/with/absolute/path/to/resource.txt
    • relative/path/to/resource.txt
    • ../../../resource.txt
    • ./resource.txt#frag01
    • resource.txt
    • #frag01
    • (empty string)
  • See: IRI, URN, URL, RDF Triple.




URI/URL Syntax: scheme: scheme-specific-part http://user:pass@example.com:992/animal/bird?species=seagull#wings \__/ \_______/ \__________/\__/\_________/\_____________/\____/ | | | | | | | protocol login host port path query anchor/fragment URN Syntax: <URN> ::= "urn:" <NID> ":" <NSS>


  • <scheme>://<authority><path>?<query>
  • New in RFC 3986 (replaces RFC 2396)


  • Uniform Resource Locator (URL)

– Subset of URI that identify resources via a representation of their primary access mechanism (e.g., their network “location”)

  • Uniform Resource Name (URN)

– Subset of URI that remain globally unique and persistent even when the resource ceases to exist or becomes unavailable – URNs are not necessarily retrievable