In Silverlight Projects I have seen using Custom Controls are vast. Now when I was studying about CustomControl I learned a lots of things on that . But in searching in internet there also various site regarding on that . MSDN is one of them good resources and others site are also available describing the CustomControl good enough. Whatever I have seen Custom Controls are like Textboxes, Text Blocks, Combo boxes, DatePickes etc . Now it is a little bit confusing that when Microsoft is providing So many controls & u can easily get it in ur ToolBox of ur VisualStudio2010 Silverlight Projects. So what is the meaning of CustomControls & I have also written the example of customcontrols like TextBoxes, DatePicker….. Well , we are going little deep of its basics.