by Peggy Barnett

Created on: July 31, 2008

An Internet URL, or Uniform Resource Locator, is the address to a Web page or file located somewhere on the Internet. Consisting of four parts, a URL request fetches a page or file from a specific server and returns the page or file to the user who requested it.

The first part of a URL is its service type and is part of the address which precedes a colon and two forward slashes. It defines the access protocol used in each request. Access protocols include the familiar, such as Hypertext Transfer Protocol, or HTTP, and the seldom used, such as Gopher. Since all requested information is transported to various types of servers, an access protocol directs a request to the correct type of server. Other access protocols include Hypertext Transfer Protocol Secure (HTTPS), for entering personal information securely, Real Time Streaming Protocol (RTSP) for multimedia requests, Simple Mail Transport Protocol (SMTP) and Post Office Protocol (POP) for email, news Protocol for Usenet groups, and File Transfer Protocol (FTP) to download and upload files. Sites residing on the World Wide Web include www. after the protocol.

The protocol is followed by the domain name and domain suffix, which identifies a specific server at a specific location. A domain name can be the name of a person, organization, server, or topic, and is followed by a dot. After the dot, the type of organization, such as a business, government institution, or educational site, is identified through suffixes, such as com, gov, and edu. If the site resides outside of the United States, there will also be another dot, followed by the code of the country where the site is located, such as uk for the United Kingdom, or jp for Japan. Domain levels can also be added to domain names to create domain names such as email.Anywhere.com. If the domain name is followed by the third part of the URL, a forward slash precedes the third portion.

On a specific server at a specific location are directories and subdirectories. The third part of the URL identifies the desired directory or subdirectory of the directory where the requested information is located. The format for this part of the URL is directory/subdirectory/subdirectory. Finally, following another forward slash, the filename of the requested object appears. If no filename is specified, a default file is retrieved.

URLs create the paths along which information traverses, making requests seem effortless. The translation of the URL into computer binary language, called an IP address, is the cog which runs along the path.

Learn more about this author, Peggy Barnett.
Click here to send this author comments or questions.