URN
A URN is a URI that uses the urn scheme to identify a logical or physical resource used by web technology, but it does not provide information to locate the object. (That would be specified in a URL). URNs are global unique persistent identifiers assigned within defined namespaces so that they will be available for long periods of time, even after the resource that is identified by it ceased to exist.
Every URN starts with urn: followed by the namespace identifier (or “path” as it is called for an URI), followed by the namespace specific string, i.e.: urn:uuid:123e4567-e89b-12d3-a456-426614174000.
The namespace specific string can be expanded with separators to pass parameters to the object that is indicated with the URN, but I have yet to see this used.
AWS uses URNs extensively. Every object that is created also is assigned a URN.