What distinguishes general relativity from a theory of gravity?

General relativity is a theory of gravity, but it is distinct from other theories of gravity in several key ways. The theory was developed by Albert Einstein and published in 1915, and it describes gravity as the curvature of space-time caused by the presence of matter and energy. This is in contrast to Newton's law of gravity, which described gravity as a force between two masses.

One of the key features of general relativity is that it predicts the existence of black holes, which are regions of space-time where the curvature is so extreme that nothing, not even light, can escape. General relativity has been extensively tested and has proven to be an accurate description of gravity in a wide variety of situations, from the behavior of planets in our solar system to the structure of the entire universe.

Other theories of gravity, such as modified Newtonian dynamics (MOND), propose alternative explanations for the observed behavior of galaxies and other astronomical objects that do not require the existence of dark matter. However, these theories have not been as extensively tested as general relativity and are not widely accepted by the scientific community.