A stellar system is a group of celestial objects that are bound together by gravity, typically centered around a star. The most common type is a solar system, which includes a star, its planets, moons, asteroids, and comets. For example, our own Solar System consists of the Sun and eight planets, including Earth. In addition to solar systems, there are also binary and multiple star systems, where two or more stars orbit each other. These systems can host their own planets and other objects. Understanding stellar systems helps astronomers learn about the formation and evolution of the universe.