What is URN?

By gobrain

Jan 24th, 2024

A URN, or Uniform Resource Name, is a type of Uniform Resource Identifier (URI) that is used to uniquely identify a resource, typically on the internet. URIs are strings of characters that provide a simple and standardized way to identify and locate resources.

Here's a breakdown of what a URN is and some key points for beginners:

What is URN

A URN is a specific type of URI that is used for the identification of resources by name in a particular namespace. Unlike URLs (Uniform Resource Locators) that provide the location of a resource, URNs are designed to be persistent and location-independent.

A URN is typically composed of a namespace identifier (NID) and a namespace-specific string.


The NID is a key component of the URN that indicates the naming authority responsible for defining the structure and semantics of the namespace.

In urn:example:resource-id, "example" is the namespace identifier.

The URN syntax is general, and various organizations or standards bodies can define their own namespaces.

For example:

  • urn:isbn:0451450523 - Identifying a book by its International Standard Book Number (ISBN).
  • urn:ietf:rfc:2648 - Identifying an Internet Engineering Task Force (IETF) Request for Comments (RFC).

URNs are often used in contexts where resource identification needs to be stable and not tied to a specific location. This is particularly useful in scenarios such as digital libraries, persistent identifiers for scholarly articles, and other long-term referencing needs.


In summary, a URN is a type of URI that provides a standardized way to uniquely identify resources by name in a persistent and location-independent manner. It's part of the broader framework of URIs that help in resource identification and retrieval on the internet.

Thank you for reading.