Gravity is known to all as a force that attracts people and objects to the surface of the Earth. But scientifically it is something much more complex.
Let's start by clarifying that gravity is not something unique to Earth, not even planets or stars. Gravity is a field, not a force (although for the force exerted by gravity we use the term gravitational force, which is why one can even admit using gravity to refer to force) that each and every body exerts. of the universe, from a black hole to an atom. What happens is that this field is directly proportional to the mass of the body that exercises it, so for very light objects we will not notice the effect.
But let's try to understand what gravity really is. It is a field, as we said, but it is not that just one mass attracts the other as if it were a magnetic field. Imagine a circular surface with an inclination towards its center, if we throw a circular object so that it rolls on this surface, it will end up going towards the center. Well, we can compare that center as a body that creates a gravitational field large enough to make our object fall on it. In fact, those who have been able to go to the house of science, in A Coruña, there is a montage that allows us to do this same experiment.
Therefore, the way in which we can understand the gravitational field is a spatial deformation in which the body that creates the field becomes the center of a "fall" (it is an example to understand us).
This space-time deformation causes a wave (gravitational wave, predicted by Einstein and recently demonstrated) that transmits the information of this deformation to the speed of light.
This post is a translation from my post: https://steemit.com/cervantes/@rccc/como-funciona-la-gravedad