Planets
A horoscope is a snapshot of the juxtaposition of the planets on the day, time and place that a native is born. In vedic astrology, the position of the planet is of great importance. The strength of the planet is determined by its placement. There are nine planets or navagrahas in vedic astrology. This comprises the Sun, the Moon, Mars, Mercury, Venus, Jupiter, Saturn, Rahu and Ketu. The last two are shadow planets.
Jupiter
Jupiter is the largest planet apart from the Sun (Sun is regarded as a planet in vedic astrology). In vedic astrology Jupiter is given great importance. He is a natural benefic and represents good fortune, luck, religion and learning. Jupiter takes approximately 12 years to complete one revolution of the zodiac. He is associated with the colour yellow. Jupiter also signifies wealth and children. He represents traditional learning and knowledge.
Jupiter rules the signs Sagittarius and Pisces. He is the lord of the stars Punarvasu, Visakha and Purva Bhadrapada. Jupiter is exalted in the sign Cancer and debilitated in Capricorn. The gem associated with Jupiter is yellow sapphire and the metal is gold.
from http://www.astropundit.com/