The Kerr solution is a solution to the equations of general relativity that describes the geometry of spacetime around a rotating black hole. It was discovered by mathematician Roy P. Kerr in 1963 and is significant because it accounts for the angular momentum of a black hole, unlike the earlier Schwarzschild solution, which describes non-rotating black holes. In the Kerr solution, the black hole is characterized by two parameters: its mass and its angular momentum. This solution leads to interesting phenomena, such as the existence of an ergosphere, a region outside the event horizon where objects cannot remain in place. The Kerr solution has important implications for our understanding of black holes and their effects on surrounding matter and light.