The solar system is a gravitationally bound system of the Sun and the objects that orbit it. It is made up of the Sun and everything bound to it by gravity, including planets, dwarf planets, moons, asteroids, comets, and meteoroids. The largest eight objects in the solar system form a planetary system of eight planets, in order from the Sun: four terrestrial planets, named Mercury, Venus, Earth, and Mars; and four giant planets, including two gas giants, Jupiter and Saturn, and two ice giants, Uranus and Neptune. The terrestrial planets have a definite surface and are mostly made of rock and metal, while the giant planets are mostly made of gas and ice. The solar system was formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud, which formed the Sun and a protoplanetary disk that gradually coalesced to form planets and other objects. The Sun is the dominant gravitational member of the solar system, and its planetary system is maintained in a relatively stable, slowly evolving state by following isolated, gravitationally bound orbits around the Sun.

Some key facts about the solar system include:

• The solar system has one star, eight planets, five officially recognized dwarf planets, at least 290 moons, more than 1.3 million asteroids, and about 3,900 comets.
• The solar system is located in an outer spiral arm of the Milky Way galaxy called the Orion Arm, or Orion Spur, and it takes about 230 million years to complete one orbit around the galactic center.
• The largest members of the solar system, apart from the Sun, are the eight major planets. Nearest the Sun are four fairly small, rocky planets - Mercury, Venus, Earth, and Mars. Beyond Mars is the asteroid belt – a region populated by millions of rocky objects. On the far side of the asteroid belt are the four gas giants - Jupiter, Saturn, Uranus, and Neptune.
• Pluto and Eris are classified as "dwarf planets".

In summary, the solar system is a collection of objects that orbit the Sun, including planets, dwarf planets, moons, asteroids, comets, and meteoroids. The largest eight objects form a planetary system of eight planets, and the solar system is located in an outer spiral arm of the Milky Way galaxy.