Difference Between URL and URI

The first difference, which is a hint for the different meaning,is what it stands for:
URI - Uniform Resource Identifier
URL - Uniform Resource Locator
A URI _identifies_ a resource by meta-information of any kind.
A URL _locates_ a resource on the net, which means if you havea URL and the appropriate protocol you can retrieve the resource.


There are many different URI, e.g.:-

URL - Uniform Resource Locator

URC - Uniform Resource Characteristics

URN - Uniform Resource Names
One characteristic of a URI is, that it gives information aboutexactly one resource. Another is there can be more than one URIdescribing the same resource.


That was the theory, here is an example:
URI: <http://www.w3.org/>

URI: <http://www.w3.org/>

URL: http://www.w3.org/pub/WWW/>
All lines describing the same resource (the URL describes the location).