Source : Free On-Line Dictionary of Computing

Universal Resource Identifier
     
         (URI, originally "UDI" in some {WWW}
        documents) The generic set of all names and addresses which
        are short strings which refer to objects (typically on the
        {Internet}).  The most common kinds of URI are {URL}s and
        {relative URLs}.
     
        URIs are defined in {RFC 1630}.
     
        {W3 specification
        (http://www.w3.org/hypertext/WWW/Addressing/URL/URI_Overview.html)}.
     
        (1997-07-16)