GR, or General Relativity, is a theory of gravitation developed by Albert Einstein in 1915. It describes gravity not as a force, but as a curvature of space and time caused by mass. According to this theory, massive objects like planets and stars warp the fabric of space-time, influencing the motion of other objects nearby. The implications of GR are profound, affecting our understanding of the universe. It predicts phenomena such as the bending of light around massive objects, known as gravitational lensing, and the existence of black holes. General Relativity has been confirmed through numerous experiments and observations, solidifying its role in modern physics.