You should use Google more...
CDC - Class (of) Device Context...
Device Context in GDI is the logical surface to draw on within your application...
http://msdn.microsoft.com/en-us/library/dd162467(v=vs.85).aspx[
^]
In .NET (C#) the closest thing to it is the
Graphics[
^] class, which is more extended, but may miss some things you need, in which case you should look into the
System.Drawing[
^] namespace of .NET...