Net output

Net output is the amount of stuff that you end up with after you have taken away all of the things that you started with.

Let's say you have a pile of 10 candies, but your friend comes over and wants to have one. You give them a candy, so now you have 9 candies left.

The net output of candies is 9 because that is the amount of candies that you have left after giving one away.

It's like counting all of the marbles you have and then taking away the ones you gave to your friend. The number you have left is the net output.