It is very difficult to trace out the origin of gravity, it is like questioning your existance itself as it dates back to millions and millions of years. However, scientists are still in the track to understand how is gravity formed at all. In brief, to know very basic of it and according to the current theory of gravity, i.e. general relativity, gravitational effects are intimately related to the nature of space and time in the universe we live in. Namely, it is formed by the deformation of spacetime by the presence of mass and energy.