Overview#
URIs, URLs, and URNs In September
2001, the
W3C issued a note clarifying the terms
URI (
Uniform Resource Identifier),
URL (
Uniform Resource Locator), and
URN (
Uniform Resource Name).
The key difference between these three categories of identifiers are:
- URI and IRI are the terms for any type of identifier used to identify a resource on the Web.
- URL is the term for any type of URI that can be resolved or de-referenced to locate a representation of a resource on the Web (e.g., Web page, file, image, etc.)
- URN is the term for a specific type of URI intended to persistently identify a resource
(i.e., an identifier that will never change no matter how often the resource moves, changes names, changes owners, etc. URNs are intended to last forever.)
There might be more information for this subject on one of the following: