Difference Between URL and URI?

Answer 1

URL- Uniform Resource Locator
URI- Uniform Resource Indentifier

URL gives you only the location of the required resource whereas URI is combination of URL and URN(Uniform Resource Name).
it provides bith the location and name of the resource. Both URL and URI are unique for each resource.

Answer 2

URL - Uniforme Resource Location
URI - Uniforme Resource Identifier

URL is a type of URI

Answer 3

Some historical notes:

https://www.w3.org/TR/uri-clarification/#confusion

https://tools.ietf.org/html/rfc3986#section-1.1.3

Although slightly orthogonal, I found the parts about fragment identifiers particulary interesting... especially its use in same-document referencing:

https://tools.ietf.org/html/rfc3986#section-4.4