Large bodies that orbit around stars. There are nine planets in our solar system. Planets are categorized into two types: gas giant planets, and terrestrial planets. Check out these links for more information about planets: SEDS' Nine Planets StarDate's Solar System Guide SFSU's Planet Search Project
In astrology the twelve celestial bodies (moving stars) of actual or reasoned nature making one horoscope different from another: Tellus, Lilith, the Moon, the Sun, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. Most modern astrologers do not count Tellus (our planet Earth) and Lilith (not an actual planet) reducing the number of planets to ten for them. Uranus, Neptune and Pluto were not considered by classical astrologers and are still ignored by most Indian astrologers leaving them with just seven planets.