Info Tech Guide

Uniform Resource Identifier (URI) identifies the name and location of a file or resource in a uniform format. It includes a string of characters for the filename and may also contain the path to the directory of the file. URIs provide a standard way for resources to be accessed by other computers across a network or over the World Wide Web.  URIs are similar to URLs in that they specify the location of a file. However, a URI may refer to all or part a URL.

The most common form of URI is the Web page address, which is a particular form or subset of URI called a Uniform Resource Locator (URL). Another kind of URI is the Uniform Resource Name (URN). A URN is a form of URI that has "institutional persistence," which means that its exact location may change from time to time, but some agency will be able to find it. 

A Uniform Resource Name (URN) functions like a person's name, while a Uniform Resource Locator (URL) resembles that person's street address. The URI rules of syntax, set forth in the Internet Engineering Task Force (IETF) Request for Comments 1630, apply for all Internet addresses. In Tim Berner-Lee's original working document, URI stood for Universal Resource Identifier.