Craters are bowl-shaped depressions found on the surface of planets, moons, and other celestial bodies. They are typically formed by the impact of meteoroids, asteroids, or comets colliding with the surface at high speeds. The force of the impact creates a cavity, often surrounded by a raised rim of material. Craters can vary in size, from small pits to large basins, and can be found on bodies like the Moon, Mars, and Earth. Some craters may also show signs of erosion or volcanic activity, which can change their appearance over time.