Rewritten URLs (sometimes known as short or fancy URLs) are used to provide shorter and more relevant-looking links to web pages. The technique adds a degree of separation between the files used to generate a web page and the URL that is presented to the world.

This URL contains query string parameters that encode blog entry dates

"http://www.example.com/Blogs/Posts.php?Year=2006&Month=12&Day=19"

but can be altered to give the user a clear idea of what he or she is going to see

"http://www.example.com/Blogs/2006/12/19/"

The second address also allows the user to change the URL to see all postings available in December, simply by removing the text encoding the day '19', and thereby saving having to navigate the GUI.

"http://www.example.com/Blogs/2006/12/"

Another example might be changing

"http://example.com/wiki/index.php?title=Page_title"

to

"http://example.com/Page_title"

The benefits of a rewrite engine are:

• Making website URLs more descriptive to improve user-friendliness and search engine optimization

• Preventing undesired "inline linking"

• Not exposing the inner workings of a web site's address to visitors

• The URLs of pages on the web site can be kept even if the underlying technology used to serve them is changed Known drawbacks:

• In some cases, for example if user modifies URL to get specified data the rewrite engine may hinder from querying. See below example:

Which is a month and which is a day?

"http://www.example.com/Blogs/2006/12/10/"

In this case, a query that would be more useful is:

"http://www.example.com/Blogs/Posts.php?Year=2006&Month=12&Day=10"