In nature, the coordinates of the center of any single gravitational influence appears to coincide with the existence of physical mass, leading to the assumption that gravity is a property of mass itself. Natural gravitational fields are also very large and it is not known with any certainty if their range has any limitation. However it is certain that the influence of gravity diminishes in a manner which is inversely proportional to the square of the distance from the gravity source. For example, the farther away you get from a planet, the faster its gravitational field fades. Yet even millions of miles away, a small influence remains.
Gravity has no known counter force such as anti-gravity. However it has been hypothesized that if gravitational fields could be synthesized and controlled, they could be used to cause matter to move in predictable ways. This would make things such as gravitational propulsion possible.