The Solar System consists of the Sun and everything that orbits around it, including 8 planets. The Sun is at the center and is the only self-luminous body, providing light and heat to the planets. The planets revolve around the Sun in elliptical orbits and reflect the Sun's light. They vary significantly in size, composition, and distance from the Sun. The four inner planets are small and rocky, while the four outer planets are large and gaseous.