Life is grand

I love being a geek. One can spend a pleasurable hour or ten looking into the difference between URI and URL. Even though I consider myself a web-developer I ashamedly admit to not knowing the difference between URI and URL. I see them used interchangeably and have left it at that for many years.

Then Ajaxian went and linked to the difference between URI and URL by Ryan McDonough. I read it and thought it made some sense and was even quite useful. The whole representation vs. identifier finally made sense.

However someone posted a comment discrediting the post and a it sparked my geek instinct. It turns out URI and URL is a well discussed topic in many internet circles with a lot of confusing RFCs, W3C specs. and conflicting forum and blog posts.

This forum discussion however seems to clear it up for me. It comes down to identifiers and locators.

isbn:1857988132 is an URI. It identifies a resource. It however does not locate it. http://www.alibris.com/books/isbn/1857988132 is an URL as it both identifies and locates a resource. An URL is a subset of URI though so, as hierarchies work, it is a URI too.

mailto:joe@soap.com is an URL and an URI.

tag:yaml.org,2002:int is an URI but not an URL as it only identifies and does not locate.

You can get a list of URI schemes (the bit in the beginning e.g. http, mailto, ftp, isbn, pop, imap etc.) that is quite fascinating.

Sadly I am still confused as to whether URL has been formally deprecated to make things simpler to understand. Some sources say it has been while others say it hasn’t. Colloquially URL will remain for a long time but technically many are saying it is deprecated.

You might still be wondering why I love being a geek. I love it because with the information I just unearthed I can better understand a complex yet robust system through its rational rules and go on to build an application that does amazing things. Things like the world wide web.

This entry was posted on Friday, November 23rd, 2007 at 7:31 pm and is filed under Post. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.