URIs represent URLs and URNs family. They have to name, describe and find the
information which are searching on internet without name and location problems.
(these problems concern URLs and URNs)
The URLs (Uniform Resource Locators)
They take care of the physical location of the resource on a known server.
The URNs (Uniform Resources Names)
URNs are independent location pointers. They allow a permanent and unique
identification of an object. Thanks to the URN, it will be always possible to
access a data and to associate to it several location. It is based on ISBN
or ISSN number principle.
For more information about URI, follow this link :
http://www.w3.org/Addressing/