Here's why:
* Free fall implies that the object is moving solely under the influence of gravity.
* No other forces are acting on it, such as air resistance or friction.
* This doesn't mean the object is necessarily falling straight down. It could be moving horizontally or at an angle, as long as the only force acting on it is gravity.
A classic example of free fall is a feather falling in a vacuum chamber. Since there's no air resistance, the feather falls at the same rate as a heavy object like a hammer.
