title: What .sdf files. How it is different from .mdf files. Does it work with linq to Sql?
body: <p>I am playing with wpf and when i have created database it is created with the .sdf files. I want to know details of .sdf files. How it is different then the standard .mdf files 
  and will they support linq to sql? Because i am not able to use it with linq files.</p>