Comments on: URI vs. URL: What’s the difference?

By: Jayasree

Jayasree — Sun, 12 Oct 2008 09:56:13 +0000

The comment posted by Xioashu Wang explains it all!!i guess it means URI is useless widout a URL??Correct me,if m wrong!!

By: Tim Erwin

Tim Erwin — Wed, 28 Nov 2007 06:31:33 +0000

URL stands for Ugly and Really Long
URI stands for Unknown and Really Insightful

*sigh*

REST stands for Really Enhanced Stupid Text

Yeah…:-)

By: Xioashu Wang

Xioashu Wang — Mon, 26 Nov 2007 23:50:36 +0000

If you want to use URL, define “location” first? Can you?

Does any place in a http URI uses IP address? None!

(1) A URI is at first a name.

(2) A URI can be bound with a suite of network protocols, such as HTTP/DNS etc., for http-URI to make it dereferencible within the web.

But whether a URI locates something or not is not determined by the composition of URI. It is dependent if a server and client software supports it.

Let me repeat:

A URI is a URL only if there is supports to make it so but not because there is some special characteristics, such as a special scheme, extension, etc., of the URI.

Is it clear?

By: John Dowdell

John Dowdell — Mon, 26 Nov 2007 22:44:20 +0000

… and it really IS pronounced “jiff”, y’know…. ;-)

(I think one of the essentials of a sound technology is being able to explain it easily. People argue about REST without saying “it’s being able to store an application state in a long ugly URL”, probably because we can’t even yet agree on what an URL is.)

By: Jon Davis

Jon Davis — Mon, 26 Nov 2007 20:55:41 +0000

"More often than not, URI is the correct term to use when referring to the location of resources on the WWW." I totally disagree. URL is not deprecated. It has a specific use. URI is *recommended* because it increases flexibility in vocabulary and applications of its use, but an [a href=".."] value or [img src=".."] is ALWAYS, ALWAYS, ALWAYS a URL in that context. (A [script src=".."], on the other hand, can be a URI; see cachefile.net.)

By: Xioashu Wang

Xioashu Wang — Mon, 26 Nov 2007 16:22:05 +0000

Why everyone is so lazy, just check the official URI specification. In section 1.1.3 of IETF RFC3986 (http://www.ietf.org/rfc/rfc3986.txt), here I quote,

“An individual scheme does not have to be classified as being just one of “name” or “locator”. Instances of URIs from any given scheme may have the characteristics of names or locators or both, often depending on the persistence and care in the assignment of identifiers by the naming authority, rather than on any quality of the scheme. Future specifications and related documentation should use the general term “URI” rather than the more restrictive terms “URL” and “URN” [RFC3305]. ”

Do we need say anything more?

By: Nameless

Nameless — Mon, 26 Nov 2007 15:37:22 +0000

19, 20 comments so far and counting. And not everyone has the same view. No wonder why everyone else still don’t know the difference. Kind of sad.

By: Marty

Marty — Mon, 26 Nov 2007 14:14:17 +0000

Remind me why I should care about this?

By: Slim Amamou

Slim Amamou — Sun, 25 Nov 2007 12:14:00 +0000

maybe you are just too lazy to read.

1- URLs are URIs
2- URLs are required to be a valid location, URIs are not

this is a valid URI whereas it is not a valid URL :

slim://md5/3a2db9eb9a4fe0db9d2a86f34f8b86e6

i can’t be more concise, if you still do not understand, you will have to read the document.

By: Eric

Eric — Sat, 24 Nov 2007 23:09:43 +0000

I’ve read far too much on this topic over the past year or so and while finding no real conclusion. Just a bunch of he said/she said. Can anyone explain this in a concise manner – in a way that won’t invoke someone else to say – um… no it’s not? It only makes me chuckle and wonder… if something like this is not relatively understood by a significant amount of technically skilled people with direct experience in the area, might it be that it’s not yet clearly established what the difference is? Perhaps it’s more analog than digital.

Oh, and wouldn’t this would make a great spam bot question :).

By: Slim Amamou

Slim Amamou — Sat, 24 Nov 2007 22:56:13 +0000

Dan Conolly wrote an excellent paper back in 2005 about this topic :

http://markkit.net/archive/www-128.ibm.com_developerworks_xml_library_x-urlni.html.html

By: Ryan J. McDonough

Ryan J. McDonough — Sat, 24 Nov 2007 17:23:41 +0000

I am the author of the original and I wanted to point out that the post DID contain A LOT of in accuracies as many commenter’s here, and at my blog, have pointed out. I have since updated that post so you may want to remove quotes you cited from the original post.

Ryan-

By: Mathieu 'p01' Henri

Mathieu 'p01' Henri — Sat, 24 Nov 2007 12:35:36 +0000

doh, I didn’t know user agents actually do the content negociation themselves :p That could come in handy.

By: AMA3

AMA3 — Sat, 24 Nov 2007 00:12:40 +0000

I agree, the article is misleading. A URI merely gives a resource a name and doesn’t say where you’ll find it. The same resource can be found at multiple locations (without regard to filename extension). A URL tells you “if you go here, you’ll find the resource” without regard to its name. However, the URL can also be used as a URI.

I try to explain the difference using examples with made-up schemes:

fuel:coal = URI (identifies/names the resource)
mine:US-PA-NewEagle-MapleCreekMine = URL (specifies an address/location)

food:Beef-Bowl = URI
restaurant:HK-Central-Yoshinoya = URL

blog:Ajaxian = URI
website:www.ajaxian.com = URL

By: Tom G

Tom G — Fri, 23 Nov 2007 22:43:02 +0000

This article is completely wrong and it makes me doubt why I’m still subscribed to this feed.

For lost souls: http://en.wikipedia.org/wiki/Uniform_Resource_Identifier describes it correctly.

By: Xioashu Wang

Xioashu Wang — Fri, 23 Nov 2007 20:18:31 +0000

You got it all wrong. It is not about if a URI is a name is a locator or not. Or if the URI has a file extension or not. (URI never has the concept of file extension, it is that you think it has a file extension. ). It is about if a URI is bound with a network protocol. In other words, if you can get something back from the URI. W3C didn’t realize this earlier. Now, the term URL and URN is deprecated because the distinction is arbitrary.

Just use URI from now on.

See the URI spec http://www.ietf.org/rfc/rfc3986.txt.

By: Site Smart

Site Smart — Fri, 23 Nov 2007 19:13:05 +0000

Thanks this was a misconception that I had. I essentially thought they were the same things. Justin Are you site smart?

By: Will Peavy

Will Peavy — Fri, 23 Nov 2007 19:00:38 +0000

From the W3C site, “Uniform Resource Identifiers (URIs, aka URLs) are short strings that identify resources in the web: documents, images, downloadable files, services, electronic mailboxes, and other resources” (source: http://www.w3.org/Addressing/#rfc3986)
…
My view is that it’s silly to bother with arguing over whether URI or URL is the “officially proper” acronym to use. If you use one of these acronyms, and the person or people you are communicating with understand the idea you’re trying to get across – then you’ve used the right acronym. If you use one of these acronyms, and people don’t understand the point you’re trying to get across – then you’ve used the wrong acronym; so try using a different term, like ‘web address’, instead.

By: Paul M. Watson

Paul M. Watson — Fri, 23 Nov 2007 18:40:01 +0000

OK, I’ve been reading an hilarious discussion (http://www.webmasterworld.com/webmaster/3215887-2-30.htm) which degenerates into acronym vs. abbreviation pedantic antics.

“A URL is a URI, but a URI is not necessarily a URL. ”

A URI can be a name, a location or both. A URL is a location and a URI. But the same string sequence can be a URI name too.

Would this be correct then:
URL (Location): mailto:joe@soap.com
URI (Name): isbn:0374479550
URI (Name): http://soap.com/joe
URL (Location): http://soap.com/joe

isbn:0374479550 != URL as it does not specify a network location. You can’t get to it. It is just an name/identifier.

By: Paul M. Watson

Paul M. Watson — Fri, 23 Nov 2007 18:10:40 +0000

A rectangle isn’t a square but a square is a rectangle. It doesn’t help much saying we should stick to URI because URL is more specific. When is it right to use URL? I understand it is a URI but it is specialised into a URL.