The Solar System is a collection of bodies that orbit around the Sun. It is known as a solar system because it orbits around a star, or sun—a star that is part of the Milky Way galaxy. The planets in this solar system are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
The Solar System is a fascinating place, filled with planets and moons that are far more interesting than you might think. The planets in the Solar System range from Mercury to Pluto and beyond, but there are also dwarf planets. 

A dwarf planet is defined by NASA as a celestial body that has enough mass to be round but not enough to clear its orbit around the sun. The term was coined by John William Herschel in 1802, and was used to describe Pluto and several other large objects that were discovered at the time. There are currently five dwarf planets: Ceres, Pluto, Haumea, Makemake, and Eris. With the exception of Ceres, which is in the main asteroid belt, these small worlds are in the Kuiper Belt. They are classified as dwarfs because they are massive, round, and orbit the Sun but have yet to clear their orbital path.

Dwarf planets are not part of this system—but they do orbit our star! They are smaller than typical planets like Saturn or Jupiter but larger than Pluto or Eris. A dwarf planet can be either an object in its own right or part of a larger group of objects orbiting another star The two largest dwarf planets are Ceres and Pluto. Both have been classified as dwarf planets since 2006 by the International Astronomical Union (IAU). Other examples of dwarf planets include Pallas Athene, Charon, Nix Andromedae Buprestis, Quaoar and Varuna.