URL - Uniform Resource Locator
It contains information about how to fetch resource from its location
Ex :- http://firsturl.com/
URL always starts with a protocol “http”, having host name and document path
URN :- Uniform Resource Name
It identifies a resource by name. It always starts with a prefix urn:
Ex :- url:number:76d76s
URI - Uniform Resource Indicator
It encompasses both URLs and URNs.
Ex :- Data URI contains information in a given way
It is not a URL nor URN because URI contains the data.