URI 和URL區別

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 have
a URL and the appropriate protocol you can retrieve the resource.

One characteristic of a URI is, that it gives information about
exactly one resource. Another is there can be more than one URI
describing the same resource.