URI

A Uniform Resource Identifiers (URI) is a string of characters that identifies unambiguously a resource. It is a standard in the WWW world.

The syntax:

uri = scheme:[//authority]path[?query][#fragment]`
authority = [[email protected]]host[:port]

Examples:

URL

A Uniform Resource Location (URL) is an URI type used to identify a resource on the Internet. It provides the

URN

A Uniform Resource Name (URN) is an URI type that identifies a given resource by name on a given namespace. For example, a book’s isbn.