Uniform Resource Locators

As you learned earlier, a URL is a pointer to some bit of data on the Web, be it a web document, a file available via FTP, a posting on Usenet, or an email address. The URL provides a universal, consistent method for finding and accessing information.

In addition to typing URLs directly into your browser to go to a particular page, you also use URLs when you create a hypertext link within a document to another document. So, any way you look at it, URLs are important to how you and your browser get around on the Web.

URLs contain information about the following:

• How to get to the information (which protocol to use: FTP, HTTP, or file)

• The Internet hostname of the computer where the content is stored (www.ncsa.uiuc.edu, ftp.apple.com, netcom16.netcom.com, and so on)

• The directory or other location on that site where the content is located

You also can use special URLs for tasks such as sending mail to people (called Mailto URLs) and running JavaScript code. You'll learn all about URLs and what each part means in Lesson 5.