What is a gravititional force?

Gravitational force is the force of attraction that exists between any two masses in the universe. This force is proportional to the mass of the two objects and inversely proportional to the square of the distance between them. It is the force responsible for the motion of the planets in the solar system, the tides on Earth, and many other phenomena in the universe. The gravitational force was first described by Sir Isaac Newton in his law of universal gravitation.