Well here is how w3.org explains it:
URI
Uniform Resource Identifier. The generic set of all names/addresses that are short strings that refer to resources.
URL
Uniform Resource Locator. An informal term (no longer used in technical specifications) associated with popular URI schemes: http, ftp, mailto, etc.
URN
Uniform Resource Name.
An URI that has an institutional commitment to persistence, availability, etc. Note that this sort of URI may also be a URL. See, for example, PURLs.
A particular scheme, urn:, specified by RFC2141 and related documents, intended to serve as persistent, location-independent, resource identifiers.
Here's the
link [ April 28, 2003: Message edited by: Michael Morris ]
