TCStyle

I've read a few tutorials online about classes in c++ and I cannot seem to get a tight grip on the concept. As of now, I realize that classes are used to represent objects (for the purpose of this thread, lets say a duck), and inside these classes there are various functions and variables that pertain to duck. I still don't see how classes can be applied to my application though. The tutorials I've read so far show me how to create the class, but don't explain the code line for line, and don't show how to actually use it.

Could someone please explain the concept behind classes, and show an example, in a dumbed-down manor, of how to use them.?