According to Einstein's theory of general relativity, gravity is not solely a property of matter but rather a property of the curvature of space-time caused by the presence of matter and energy.
In general relativity, matter and energy, including mass, particles, and even forms of radiation, create what is known as a gravitational field. This gravitational field is a manifestation of the curvature of space-time, which is the fabric of the universe. The presence of matter and energy curves or warps space-time, and the curvature of space-time determines how objects move in the presence of gravity.
In this framework, the gravitational force that we perceive is a consequence of objects following the curvature of space-time rather than being directly exerted by one object on another, as in Newtonian gravity. Objects, including light, move along geodesics, which are the paths determined by the curvature of space-time.
So, gravity can be understood as the result of matter and energy telling space-time how to curve, and the curved space-time, in turn, influences how matter and energy move. This mutual relationship between matter, energy, and space-time is described by Einstein's field equations in general relativity.
In summary, gravity is a property of the curvature of space-time caused by the presence of matter and energy. It is the way in which matter and energy shape the fabric of the universe, determining how objects move and interact with each other.