In the universe, there exists a force of attraction between any two particles or objects. The force of gravity is the force with which the earth, moon, or other massively large object attracts another object towards itself. This attractive force is called gravitational force. The magnitude of this force is proportional to the product of mass of the two objects or particles and inversely proportional to the square of distance between them. Scientists believe that mutual exchange of a kind of particles between two bodies is responsible for gravitational attraction between the bodies. Particle of this kind is named gravitation.
The gravitational force is a force that attracts any two objects with mass. We call the gravitational force attractive because it always tries to pull masses together, it never pushes them apart. In fact, every object, including you, is pulling on every other object in the entire universe! This is called Newton’s Universal Law of Gravitation.