Supper or Dinner what is the difference. ?

So, you are having supper of are you having dinner. Someone can say dinner is before sunset, and supper is after sunset. 

The truth is that dinner can be applied to any meal, even breakfast, even though that dinner is applied either to lunch or last meal of the day. 

Yes, to keep it simple supper simply means the last meal of the day, and maybe snack-time after dinner. :) (end).