A moon is a type of celestial body that orbits a planet. Moons can vary in size, composition, and the nature of their orbits, with some being rocky and others icy or gaseous. Earth's moon, for instance, is a solid, rocky body that has a significant effect on our planet, notably regarding ocean tides. Moons are found orbiting many planets in the solar system, including gas giants like Jupiter, which boasts dozens of moons. They play important roles in their respective systems, influencing planetary conditions, atmospheres, and even providing potential sites for exploration and scientific research.