NOT gate

Imagine you have a machine that can either open or close a door. A NOT Gate is a machine that takes in one input and does the opposite of what it was given. So, if the input to the NOT Gate is "open the door," it will do the opposite and "close the door." If the input is "close the door," it will do the opposite and "open the door." It's like magic! It's called a NOT Gate because it does the opposite (or "not") of what it's given.