The Feng Shui Bagua Map is sometimes called The Magic Square. The importance is that each small square within the Magic Square represents a Life Area that presents important considerations for us. Due to their tripartite structure, they are often referred to as "trigrams" in English.

The trigrams are related to Taiji philosophy and the Wu Xing. The ancient Chinese classic I Ching consists of the 64 pairs of trigrams (called "hexagrams") and commentary on them. The interrelationships among the trigrams are represented in two arrangements, the Primordial (先天八卦), "Earlier Heaven" or "Fuxi" bagua (伏羲八卦), and the Manifested (後天八卦), "Later Heaven," or "King Wen" bagua. The trigrams have correspondences in astronomy, astrology, geography, geomancy, anatomy, the family, and elsewhere.

The eight trigrams are:

* Qian 天 "Heaven"
* Xun 風 "Wind"
* Kan 水 "Water"
* Gen 山 "Mountain"
* Kun 地 "Earth"
* Zhen 雷 "Thunder"
* Li 火 "Fire"
* Dui 泽 "Lake"

The five elements of feng shui are air, fire, earth, wood, and water.

There are two possible sources of bagua. The first is from traditional Yin and Yang philosophy. The interrelationships of this philosophy were described by Fuxi in the following way:

無極生有極、有極是太極、
太極生兩儀、即陰陽;
兩儀生四象: 即少陰、太陰、少陽、太陽、
四象演八卦、八八六十四卦
The Limitless (Wuji) produces the delimited, and this is the Absolute (Taiji)
The Taiji produces two forms, named yin and yang
The two forms produce four phenomena, named lesser yin, great yin (taiyin also means the Moon), lesser yang, great yang (taiyang also means the Sun).
The four phenomena act on the eight trigrams (ba gua), eight eights are sixty-four hexagrams.

Another philosophical description of the source is the following, attributed to King Wen of the Zhou Dynasty: "When the world began, there was heaven and earth. Heaven mated with the earth and gave birth to everything in the world. Heaven is Qian-gua, and the Earth is Kun-gua. The remaining six gua are their sons and daughters".

The trigrams are related to the five elements of Wu Xing. The Water and Fire trigrams correspond directly with the Water and Fire elements. The element of Earth corresponds with both the trigrams of Earth and Mountain. The element of Wood corresponds with the trigrams of Wind (as a gentle but inexorable force that can erode and penetrate stone) and Thunder. The element of Metal corresponds with the trigrams of Sky and Lake.