The Kepler-186 System is a star system located about 500 light-years away in the constellation Cygnus. It is notable for containing the first Earth-sized exoplanet, Kepler-186f, discovered in the habitable zone of its star, Kepler-186. This zone is where conditions may allow for liquid water to exist. The system consists of five planets, all orbiting a K-dwarf star, which is cooler and smaller than our Sun. The planets range in size and distance from their star, with Kepler-186f being the most similar to Earth in terms of size and potential for habitability.