A stone, when released from the hand, falls towards the earth due to gravitational force. The gravitational force acts both on the stone and the earth. The stone attracts the earth with the same force by which the earth attracts the stone. Since, the stone’s mass is very small as compared to the earth’s mass, so acceleration produced in the stone is very large but that in the earth is negligible. Thus, the earth’s motion is not noticed, whereas that of the stone is.