Difference among URI, URL, URN

□ URI(Uniform Resource Identifier) : Address indicating resource on the Internet. It is implemented as a URL or URN format(URI ⊃ URL, URN).

□ URL(Uniform Resource Locator) : "Protocol://Server address:Port/Resource path" format of address representation. When the server address is changed, also changed the location of the resource.

□ URN(Uniform Resouce Name) : "urn:Namespace:Resource name" format of address representation. regardless of server address, Path of the resource is same