Gravity is one of the most basic forces in nature.
The gravitational force of the Sun keeps the Earth in its orbit around the Sun. Sir Isaac Newton, in 1766, described gravity mathematically as that of the mutual attraction or force between two bodies that is a function of their masses and the distance between them. The strength or magnitude of gravity depends directly on the mass of the two bodies and inversely on the square of the distance between them. Mass is a fundamental property of the substance making up a particle or object. You weigh more on the Earth than on the Moon, but your mass is the same in both places.