URLThe "address" of any particular web page or other element of content on the Internet. The URL includes a Domain Name which is a unique name consisting of a string of alphanumeric characters and dashes separated by periods, that maps to IP numbers. The Top Level Domain (TLD) or Extension identifies an organization, group, or purpose for the site.
Example:
URL:http://www.cdc.gov/reproductivehealth/adolescentreprohealth/index.htm
Domain Name: www.cdc.gov
Extension: .gov