Custom controls and Web Parts can make you more productive by enabling you to create re-usable components for your WebForms. You can package up a piece of your user interface and re-use it within your Web site or across many Web sites. But that’s only one way that these controls make you more productive. If you’ve ever had an control that you wished worked slightly differently, you can now create the control that you want. When you build your own custom controls and Web Parts, you can have the control do as much (or as little) as you want