Difference between URI and URL

Key Difference: A URI (Uniform Resource Identifier) is a string of characters that is used to identify a name or a resource. It can be classified further as URL and URN. URL is a string of characters that point out the address of the resource.

Even with the computer boom, a lot of people still have not yet gotten the lingo that goes with computers. There are a lot of words that still confuses people that are not tech savvy and in some cases even the tech savvy people. The technical terms of some of the technologies we use are never even heard of. One such technology is the URI, URL and URN. These terms are commonly used when referring to links on the Internet for websites.

A URI (Uniform Resource Identifier) is a string of characters that is used to identify a name or a resource. URIs can be classified as URL (Uniform Resource Locator), URN (Uniform Resource Name) or both. So in any case a URI is also a URL and a URN. The URN is the name of the resource, while the URL is the address where the resource is located. Both of these together form the URI. An example would be a person’s name can be considered as a URN, while the person’s address can be considered as the URL. Either one of these could be used to identify the person; hence they both can be URI. IETF (Internet Engineering Task Force) and W3 are the organization that set the standards for the World Wide Web. They explain the URL and URI as, "URL is a useful but informal concept: a URL is a type of URI that identifies a resource via a representation of its primary access mechanism (e.g., its network "location"), rather than by some other attributes it may have."

The unique ISBN coding system that is used for identifying books can be used as an example for URN. ISBN 0-486-27557-4 points to a specific edition of Shakespeare's play Romeo and Juliet. This only shows what the number points too, however it does not provide the location of the book or how to access it, which would be the job of a URL. The URL for the book would be something like this file:///home/username/books/. Either one of these or both of these could be refer to as URI for the book.

In layman’s terms, a URI is any string of characters that can identify the resource. A URL is a string of characters that provides the location of the resource while allowing the person to access the resource as well. A URN is just the name of the resource and does not indicate anything else. A URL and URN are both parts of the URI. In conversation today, both the URI and URL are known as URL, though in many cases these are right.

Examples of URL: