The Schwarzschild solution is a solution to the equations of general relativity proposed by Karl Schwarzschild in 1916. It describes the gravitational field outside a spherical, non-rotating mass, such as a planet or a black hole. This solution is significant because it provides insights into how gravity behaves in the vicinity of massive objects. In the Schwarzschild solution, the geometry of space and time is altered by the presence of mass, leading to phenomena like gravitational time dilation and the formation of event horizons. It serves as a foundational model for understanding black holes and the effects of gravity in the universe.