Uniform Resource Locator
a standard string of characters that identifies an object or service on the basis of where it is stored on a network (especially the web) and the protocol necessary to access it
URL and Uniform Resource Identifiers (URI) are often used synonymously. See citation under Uniform Resource Identifier.
RFC 3986, 2005The term "Uniform Resource Locator" (URL) refers to the subset of URIs that, in addition to identifying a resource, provide a means of locating the resource by describing its primary access mechanism (e.g., its network "location").