Centrifugal force
Example: If John is in a car that takes a sharp right turn, he will feel as though he is being pushed to his left. This is an imaginary force, called a centrifugal force, or a "running away from the center" force. John feels it because he is inside the car and is affected by it. However, if John's friend, Andy, is on the side of the road facing the front of John's car and watches John's car take a sharp right turn, Andy will see the car push John to the right with the car as it changes direction. This is a real force called centripetal force (or an "aiming towards the center" force) and acts towards the center of the circle of rotation.