Albert Einstein is renowned for the theory of relativity, which revolutionized the understanding of space, time, and gravity. Published in two parts, the Special Relativity in 1905 and the General Relativity in 1915, Einstein's theories introduced groundbreaking concepts, including the idea that time and space are interwoven into a single continuum and that massive objects can warp space-time. This work not only altered the field of physics but also had profound implications for cosmology, influencing our comprehension of black holes, the expanding universe, and gravitational waves. Einstein's contributions have left an indelible mark on science and technology.