What are ARKs?
ARKs (Archival Resource Keys) are high-functioning identifiers that lead you to things and to descriptions of those things.
For example, this ARK gets you a thing: https://n2t.net/ark:/67531/metadc107835/
You can add a '?' to get a description: https://n2t.net/ark:/67531/metadc107835/?
What's an identifier?
On the internet, an identifier is a URL or part of a URL. For example, this core ARK identifier,
is carried below inside two different URLs (Uniform Resource Locators, or web addresses):
https://gallica.bnf.fr/ark:/12148/btv1b8449691v/f29
https://n2t.net/ark:/12148/btv1b8449691v/f29
ARKs are especially good at being persistent identifiers.
What's a persistent identifier?
The average lifetime of a URL has been said to be 44 days. The lifetime the period after which you can expect a typical published URL to give you the well-known and dreaded 404 Not Found error. Irritating as that can be, it's a disaster for libraries, archives, museums, and other memory organizations. They want persistent identifiers, that should continue to work far into the future.
How do ARKs differ from DOIs, Handles, PURLs, and URNs?
Those are all major kinds of persistent identifier solutions that appeared between 1994 (Handles) and 2001 (ARKs). The short answer: ARKs are the the only mainstream, non-siloed, non-paywalled, actionable identifiers. There are over 3.2 billion ARKs in the world, and no one ever paid for the right to create or use them.
I've heard of ORCIDs and UUIDs in the context of persistent identifiers. Where do they fit in?
ORCIDs are specifically designed to identify researchers, and they often link to research works using the other persistent identifiers. UUIDs are globally unique strings that are very easy to create but that don't become usable as web addresses until you put them inside a URL; that people often carry around inside URLs, or inside any of the above identifiers; they're great because they're easy to create, but you need to choose a way to carry
