A Uniform Resource Locator, URL, or Web address, is a standardised address name layout for some resource (such as a document or image) on the Internet. It provides the address for locating information on the Internet.

The following example illustrates the difference between a URL and a domain name:

URL: http://www.example.com

Domain name: example.com
Subdomain: www

The domain name is made up of the domain + top level domain. eg.
Domain: example
Top level domain: com

So, in its simplest terms, the domain name is the overall web site identifier and the URL is the locator for a particular resource on the Internet. Most domain names point directly to an index file, so entering the domain name in the forum http://www.example.com will take you to the index or base home file for that web site (eg. http://www.example.com/index.php).