Definition

A Uniform Resource Name (URN) is a permanent identifier within a wider Uniform Resource Identifier (URI) system. URNs identify the resource itself instead of its locations.

They are among the three primary types of URIs, with the other two being the Uniform Resource Characteristics (URCs) and the Uniform Resource Locators (URLs).

How Do Uniform Resource Names Operate?

A Uniform Resource Name (URN) offers a distinct and consistent identifier for a resource without essentially indicating where it is located. The identifiers should be universally distinct and persistent over time. Upon assignment, the URN must stay unaltered, even when the resource is relocated.

Moreover, Uniform Resource Names often begin with the ‘urn:’ prefix, then the namespace identifier (NID) follows for the accountable naming authority and the resource’s namespace-specific string (NSS). For instance, ‘urn:isbn:0451450523’ corresponds to the 1968 book, The Last Unicorn, with ‘isbn’ (International Standard Book Number) acting as the NID and ‘0451450523’ as the NSS.

Uniform Resource Name (URN) namespaces are regularly hierarchically organized to prevent conflicts. In our example above, you may create sub-namespaces for various publishers to ensure that their identifiers are distinct within their respective namespaces.

Advantages and Applications of URN

URNs have many benefits and use cases like the following: