General relativity is a theory of gravitation proposed by Albert Einstein in 1915. It describes gravity not as a force, but as a curvature of space and time caused by mass. Massive objects, like planets and stars, warp the fabric of the universe, creating a "dip" that smaller objects follow, which we perceive as gravitational attraction. This theory revolutionized our understanding of the universe, explaining phenomena such as the bending of light around massive objects and the expansion of the universe. It has been confirmed through various experiments and observations, including the detection of gravitational waves and the precise movement of planets.