URN
Uniform Resource Name
ELI5 — The Vibe Check
A URN names something uniquely without saying where to find it. Like a person's Social Security Number — it uniquely identifies them but doesn't tell you their address. ISBNs for books are URNs. They're part of the URI family but don't help you actually fetch the resource.
Real Talk
A URN is a URI with the scheme 'urn:' that provides a persistent, location-independent identifier for a resource. Format: urn:namespace:specific-string (e.g., urn:isbn:0-486-27557-4). URNs are meant to identify resources even if their location changes.
When You'll Hear This
"URNs are used in XML namespaces and some API specifications." / "The ISBN is technically a URN."
Related Terms
URI (Uniform Resource Identifier)
A URI is the general term for any identifier of a resource. URLs are URIs that tell you WHERE and HOW to get something.
URL (Uniform Resource Locator)
A URL is the complete web address of something on the internet — the full 'how to get there' including the protocol, domain, path, and any query parameters...