There are two scenarios for taking the user from one page to another:
User won’t see the real URL
You don’t want the user to know the real page you are transferring the control to. That is, the URL window of the browser wouldn’t show the address of the page you have really transferred the user to. For example, the browser URL shows specal-customer.aspx, but you have actually transferred the user to customer.aspx?type=special.
The re-writing of path (RewritePath) is described in the following article:
User sees the real URL
In this second case, you want to transfer the control to entirely different page. With this, the user will, of course, see the url in browser’s url window. This can be accomplished by setting the Redirect method of the Response object that is available from an aspx page.