URL

in full Uniform Resource Locator

Address of a resource on the Internet. The resource can be any type of file stored on a server, such as a Web page, a text file, a graphics file, or an application program. The address contains three elements: the type of protocol used to access the file (e.g., HTTP for a Web page, ftp for an FTP site); the domain name or IP address of the server where the file resides; and, optionally, the pathname to the file (i.e., description of the file's location). For example, the URL http://www.britannica.com/heritage instructs the browser to use the HTTP protocol, go to the www.britannica.com Web server, and access the file named heritage.

(Uniform Resource Locator) The address that defines the route to a file on an Internet server (Web server, FTP server, mail server, etc.). URLs are typed into a Web browser to access Web pages and files, and URLs are embedded within the pages themselves as hypertext links. The URL contains the protocol prefix, port number, domain name, subdirectory names and file name. If a port number is not stated in the address, port 80 is used as the default for HTTP traffic.

Downloading the Home Page
To access a home page on a Web site, only the protocol and domain name are required. For example, HTTP://WWW.COMPUTERLANGUAGE.COM retrieves the home page of The Computer Language Company's Web site. The HTTP is the Web protocol, and WWW.COMPUTERLANGUAGE.COM is the domain name. Browsers default to the http:// prefix so only the www.computerlanguage.com needs to be typed in. In fact, you can usually omit the WWW and dot, because most Web sites treat blank host names as "www" host names. Sometimes, you can even omit the .com, and the browser fills it in automatically.

Another Web Page
If a page is not the home page, its name has to be part of the address, and a slash is used to separate it from the domain name. For example http://www.computerlanguage.com/aboutus.htm points to the About Us page (aboutus.htm file).

The Full Path
If a page is stored in a subdirectory (folder within a folder), its name is also separated by a slash, and subdirectories can be several levels deep. For example, the components of the following hypothetical URL are described below:

  http://www.clothes.com/mens/shirts/formal.html

   http:             protocol
   //                separators
   www.clothes.com/  domain name
   mens/             subdirectory name
   shirts/           subdirectory name
   formal.html       document name (Web page)

Is It a URL or a URI?
Technically, a URL is a type of uniform resource identifier (URI). Since most URIs are URLs, "URL" is the term more commonly heard. See URI.

URL - Uniform Resource Locator