„URLs were never intended to be what they’ve become… Unfortunately, we’ve never been able to standardize URNs, which would give us a more useful naming system.“ — Dale Dougherty, 1996⠀⠀
In 1992 Tim Berners-Lee created three things, giving birth to what we consider the Internet: The HTTP protocol, HTML, and the URL. His goal was to use all three to. bring hypertext – documents linked to one another – to life. ⠀
Let’s step back and make sure we know what URLs and URNs are. ⠀
⭐️ URL or Uniform Resource Locator is an address of a file on a server such as a web page, a text or a graphics file. It contains three elements: the type of protocol used to access the file (typically HTTP), the domain name or IP address of the server where it is stored and, optionally, the pathname to the file.⠀
⭐️ URN or Universal Resource Name identifies a file by its name, not its address. Each URN is made of two components: an authority who can resolve that URN and the specific ID of this document in whichever format. For example, urn:isbn:0131103628 will identify a book by its ISBN number.⠀
How is a URN better? ⠀
So a URN is like a person’s name, while a URL is like their address. A URN identifies an item while a URL provides a method for finding it. Which makes URNs permanent reference unlike a URL. They can also never change or break, are globally unique and persistent over long periods of time (basically forever).⠀
Better but never used ⠀⠀
In 1993 web community believed that the URL would die in favor of the URN. It’s 2020 and it has still not happened. Why?⠀
👉🏼 To craft a URN of a file or a page you cannot just take its location like in case of a URL. You need to come up with a name, and one idea was to use a cryptographic hash of the page content which would look something like: urn:791f0de3cfffc6ec7a0aacda2b147839. The problem was it wasn’t clear how to turn that hash into a piece of real content and how to support format changes which often happen to files. ⠀
👉🏼 Another idea. The Web was originally created on the funding and for collaboration of physicists, no mater how general-purpose Tim-Berners Lee wanted it to be. And these physicists needed a way of linking of and searching for information. Compare how much more information can a URL hold as opposed to a URN:
URL ▶️ https://harvard-physics.com/mechanics/kinematics/velocity-vs-acceleration
URN ▶️ urn:harvard:9362813110
👉🏼 Or, who knows, maybe there were some more authoritative people supporting the idea of a URL over a URN 🤗
I can go on and on speculating, but the fast is: If you can get lots of people to use something, it becomes a standard. And if no one uses a technology, no matter how technically perfect it is, it exists only on paper (best case).
😃 Fun fact: Now that virtually all content is hosted over HTTP and in www, it is not necessary to specify https://www. As early as 1996 browsers were already inserting it automatically.
This post is partially based on this article.