Gravitation is a universal force of attraction acting between all matter.
Gravitation holds the universe together.
Although the effects of gravity are easy to see, an explanation for gravitational force has puzzled people for centuries. Newton's theory of gravitation says that the gravitational force between two objects is proportional to the size of their masses. The gravitational force is inversely proportional to the distance between the centres of mass of the two objects squared. Newton's was presented by Einstein in his general theory of relativity. Einstein perceived a gravitational field as a geometrical warping of four-dimensional space and time.