Definition: A URL is a specially-formatted text string that defines a location on the Internet. URL strings contain three parts or substrings:
-
1. network protocol
2. host name or address
3. file location
|
The network protocol substring determines the underlying Internet protocol to be used in reaching the location. These strings consist of a standard protocol name followed by the :// characters. Typical protocols found in URLs include http://, ftp://, and mailto://.
The host substring immediately follows the protocol defintion. Hosts may be defined by Internet-standard naming (DNS) or by IP address. For example, a URL of of http://compnetworking.about.com or, equivalently, http://209.143.212.20 contains the protocol and host information needed to access this Web site.
The file location portion of a URL defines the location of a network resource. Resources are files that can be plain text files, documents, graphics, or programs, and resource names are relative to a local root directory. Technically, a URL like http://compnetworking.about.com contains an implied file location of /, that Web servers like Apache automatically translate to a specific file name like index.htm. All other specific files exist in a hierarchy or directory tree underneath the root, such as the following:
RELATIVE FILE LOCATION
/library/glossary/blglossary.htm
COMPLETE URL
http://compnetworking.about.com/library/glossary/blglossary.htm
When creating HTML pages, the author can choose to use either the relative file locations or complete URLs. A user of the Internet generally works with complete URLs.
Also Known As: Uniform Resource Locator
Related Resources:
Basic Networking Directory
Learn more about computer networking from the ground up through these online resources.
