The Solar System consists of the Sun and everything that orbits it, including 8 planets, over 100 moons, asteroids, comets, and other objects. The 4 inner planets are small and rocky, while the 4 outer planets are large gas giants. The document describes each planet's characteristics such as composition, size, orbital period, and presence of moons and rings. It explains that the Sun is much larger than the planets and provides their light and heat through nuclear fusion in its core.