The theory of General Relativity, formulated by Albert Einstein in 1915, revolutionized our understanding of gravity and the nature of spacetime. This theory proposes that gravity is not a force transmitted between masses, but rather a curvature of spacetime caused by mass and energy. In this abstract, we provide a concise overview of the key principles and implications of General Relativity. We discuss the equivalence principle, which states that inertial and gravitational mass are indistinguishable, leading to the geodesic motion of particles in curved spacetime. The Einstein field equations, a set of nonlinear differential equations, describe how matter and energy distribution determine the curvature of spacetime. These equations predict the behavior of gravitational waves, the bending of light in a gravitational field (gravitational lensing), and the existence of black holes. General Relativity has been confirmed through various experiments and observations, including the deflection of starlight during a solar eclipse and the recent detection of gravitational waves. Its profound influence on cosmology and our understanding of the universe's large-scale structure continues to drive scientific inquiry and shape our comprehension of fundamental physics.