Hey so a surplus means, if you have 'something left over' so this can be anything. It is not necessarily a profit. It can also be that you ordered vegetables and fries and you leave 2 fries and 1 broccoli on your plate, that would then be your surplus.
In this case I'm referring to, you earn some money, pay your bare essentials, how much do you have left :)
I would call a surplus and profit the same thing because I think of profit as an excess of value not just of Rothschild centralized money but also of natural resources and other things too. But I do agree that we are save as much as we can. A penny saved is a penny earned and oatmeal saved is oatmeal exploding in your face haha.