Albert Einstein is renowned for formulating the theory of relativity, which revolutionized the understanding of space, time, and gravity. Published in two parts—special relativity in 1905 and general relativity in 1915—Einstein's theories challenged traditional Newtonian physics. Special relativity introduced the concept that the laws of physics are the same for all non-accelerating observers and that the speed of light is constant in a vacuum. General relativity expanded this framework, showing that massive objects can warp space-time, affecting the gravitational pull experienced by other objects. These theories have had profound implications in physics, influencing everything from cosmology to GPS technology and enhancing comprehension of the universe.