A URL is actually a link, which connects you to a website. It is also called as a Uniform Resource Locator. This is a unique address for a file that is accessible on the Internet. eg. http://www.website.com/products/laptop.html 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. The target website is contacted using a hypertext transfer protocol, which identifies the website and transfer the contents to the end user. The Uniform Resource Locator was created in 1994 by Tim Berners-Lee, Marc Andreessen, Mark P. McCahill, Alan Emtage, Peter J. Deutsch and Jon Postel, as part of the URI. The URL consists of various components to describe the full length of it.
Every URL consists of the 1) the scheme name or protocol followed by a colon, then depending on scheme, 2) a hostname (server name or alternatively an IP address), 3) a port number, the path of the resource to be fetched or the program to be run, then, for programs such as Common Gateway Interface (CGI) scripts, 4) a query string and with HTML documents an anchor (optional) for where the page should start to be displayed.
The basic components in a URL are:
http: //www.website.com /products/ laptop.html
protocol server name directory name page or file name
1) Protocol comes first and ends with a colon eg. http:
2) Server name comes then, prefixed with a double slash eg. //www.website.com
Server name further divided into:
a) Server's name eg. www
b) Domain name eg. website.com
3) Directory which comes next with slashes before and after eg. /products/
4) Actual Page / file name comes last eg. laptop.html
A URL for a particular image on a web site will look like this:
http://searchnetworking.website.com/animals/images/koala.gif
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:
ftp://www.somecompany.com/whitepapers/widgets.ps
A URL to email a message to someone would be like this:
mailto:somebody@mail.com