I don't understand why we would use the "Not" statement because all it does it make the outcome opposite? True is changed to false and false is changed to True.
This is the simplified version.
Lets say you have a variable that you want to pass through an object, and you want to effect everything that isn't that variable. This would be a lot better if the variable was an integer instead of a Boolean in that regard because you can say that any number (Other than the number given by your variable) is usable. This is for more advanced programming and in essence is not required, but useful if you know how to utilize it.