Albert Einstein was a theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics. In 1905, his 'Annus Mirabilis' (miracle year), he published four groundbreaking papers on the photoelectric effect, Brownian motion, special relativity, and the equivalence of mass and energy (E=mc²). These works revolutionized our understanding of space, time, and gravity. Einstein won the Nobel Prize in Physics in 1921, not for relativity, but for his discovery of the law of the photoelectric effect. A Jewish refugee from Nazi Germany, he eventually settled in the United States. Beyond physics, Einstein was a vocal advocate for peace, Zionism, and civil rights. His name has become synonymous with 'genius' and his work continues to influence everything from GPS technology to our understanding of black holes.