Hi Sathish,

User control is nothing but when ever create user control it will be created .ASCX file,main purpose of this is reduced the data redendency of the Application, Custom control is the created that will be created the DLL file.

User Control                                                                   Custom Control

1.it will created ASCX file                                                 1.It will created the DLL file

2.it is Local to the Application                                       2.It is Globale to the application

3.It can be Add to the Solution Only                               3.It can be Add to the Toolbox

Thanks,

Narasima