antiderivative

An antiderivative is just like a regular derivative, only backwards! The derivative of something tells us how much it changes as we move a little bit, but an antiderivative tells us how much it has changed when we add up all of the little changes. It's like a big running total of how much something has changed since the very beginning! It's like a big puzzle, and if you want to solve the puzzle, you have to figure out what the antiderivative is.