A URL (Uniform Resource Locator, previously Universal Resource Locator) - usually pronounced by sounding out each letter but, in some quarters, pronounced "Earl" - is the unique address for a file that is accessible on the Internet. A common way to get to a Web site is to enter the URL of its home page file in your Web browser's address line. However, any file within that Web site can also be specified with a URL. Such a file might be any Web (HTML) page other than the home page, an image file, or a program such as a common gateway interface application or Java applet. The URL contains the name of the protocol to be used to access the file resource, a domain name that identifies a specific computer on the Internet, and a pathname, a hierarchical description that specifies the location of a file in that computer.
On the Web (which uses the Hypertext Transfer Protocol, or HTTP), an example of a URL is:
which specifies the use of a HTTP (Web browser) application, a unique computer named www.ietf.org, and the location of a text file or page to be accessed on that computer whose pathname is /rfc/rfc2396.txt.
A URL for a particular image on a Web site might look like this:
A URL for a file meant to be downloaded using the File Transfer Protocol (FTP) would require that the "ftp" protocol be specified like this hypothetical URL:
A URL is a type of URI (Uniform Resource Identifier, formerly called Universal Resource Identifier.)