The planets are large celestial bodies that orbit around a star, such as the Sun. In our solar system, there are eight recognized planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Each planet has unique characteristics, including size, composition, and atmosphere. Planets can be classified into two main categories: terrestrial and gas giants. Terrestrial planets, like Earth and Mars, are rocky and have solid surfaces. Gas giants, such as Jupiter and Saturn, are composed mainly of gases and lack a well-defined solid surface. Understanding these planets helps us learn more about our solar system and the universe.