Velocity: The rate of change of displacement with respect to time. In simpler terms, it measures how fast or slow something is moving.
Deceleration (Negative Acceleration): When an object slows down due to negative acceleration. For example, when you press the brakes in a car, it decelerates.
Free Fall: The motion of an object under only gravitational force without any other forces acting on it. When an object is dropped from a height, it experiences free fall.