In the .NET Framework 3.5 SP1, Microsoft introduced ASP.NET Routing, which decouples the URL of a resource from the physical file on the web server. With ASP.NET Routing you, the developer, define routing rules map route patterns to a class that generates the content. For example, you might indicate that the URL <code>Categories/<i>CategoryName</i></code> maps to a class that takes the <i>CategoryName</i> and generates HTML that lists that category's products in a grid. With such a mapping, users could view products for the Beverages category by visiting <code>www.yoursite.com/Categories/Beverages</code>.In .NET 3.5 SP1, ASP.NET Routing was primarily designed for <a href="http://www.asp.net/mvc/">ASP.NET MVC</a>