The theory of general relativity was developed by Albert Einstein. Introduced in 1915, this groundbreaking theory revolutionized the understanding of gravity, proposing that it is not a force but rather a curvature of spacetime caused by mass. This concept explains how massive objects, such as planets and stars, influence the motion of other objects in their vicinity. General relativity has profound implications for various fields, including astrophysics and cosmology, providing insights into phenomena like black holes, gravitational waves, and the expansion of the universe. It remains one of the cornerstones of modern physics, fundamentally changing how we perceive space and time.