Gravity is a major player in the study of physical science. It is, of course, the force of gravity that causes objects to fall. One object always exerts a force of attraction on another object. This force of attraction is a pull, like the pull of gravity.
The larger an object is, the greater is the force of its attraction. Consider the fact that the sun, which is much, much larger than the earth, can, even at 90 million miles away, hold the earth and the other eight planets in orbit.