Ancient Chinese astronomers referred to the five major planets by the names of the element they were associated with: Venus corresponds to Metal (gold); Jupiter to Wood; Mercury to Water; Mars to Fire; Saturn to Earth.
As with most astrological systems Chinese Astrologers believed a person's destiny could be determined by the positions of the major planets, the positions of the Sun, Moon and comets and the person's time of birth and the corresponding zodiac birth sign.
This complex system is based upon the twelve year cycle of the orbit of Jupiter. (11.86 years in reality but who is counting?}.
The combination of 5 elements × 12 animal zodiac signs creates a 60-year cycle, which starts with the Wood Rat and ends with Water Boar.
If the year ends in 4 it is Yang Wood. If the year ends in 5 it is Yin Wood.
Wood is associated with the East, Spring, the planet Jupiter, the color green and the llver and gallbladder.
People ruled by Wood are generous, warm, persuasive, co-operative. They seek to expand and grow. The are idealistic, ethical, enthusiastic and seek to explore.
Wood 'Governs' the Tiger, Rabbit, Dragon
Here is the simple character for wood in wood.