Control Class

The Control class is in the System.Windows.Forms namespace. It serves as a base class for the Windows controls you'll see, such as text boxes. For example, here's the class hierarchy for text boxes, where the MarshalByRefObject class is derived from the Object class, the Component class is derived from MarshalByRefObject-all the way through the Control class and up to the TextBox class:

Object
   MarshalByRefObject
      Component
         Control
            TextBoxBase
               TextBox

for more information about control class you can visit to MSDN :

Control class : http://msdn.microsoft.com/en-us/library/system.windows.forms.control.aspx

Control members : http://msdn.microsoft.com/en-us/library/system.windows.forms.control_members.aspx