The term "solar system" refers to the sun and all the bodies that are caught in its gravitational field. This includes the eight planets, several dwarf planets, the moons and a variety of asteroids and comets.
The eight planets of the solar system in order of their distance to the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The three largest dwarf planets include Pluto, Eris and Ceres.
Pluto was originally classified as a ninth planet, but this changed in 2006 when the International Astronomical Union (IAU) stopped recognizing Pluto as a planet and downgraded it to a dwarf planet.