Feng Shui is an ancient Chinese system of aesthetics believed to use the laws of both Heaven (astronomy) and Earth (geography) to help one improve life by receiving positive Qi. Qi (roughly pronounced as the sound 'chee' in English) is a movable positive or negative life force which plays an essential role in Feng Shui. In Feng Shui as in Chinese martial arts, it refers to 'energy', in the sense of 'life force' or élan vital. A traditional explanation of Qi as it relates to Feng Shui would include the orientation of a structure, its age, and its interaction with the surrounding environment including the local microclimates, the slope of the land, vegetation, and soil quality.
The term Feng Shui literally translates as "wind-water" in English. This is cultural shorthand taken from the following passage of the Zangshu (Book of Burial) by Guo Pu of the Jin Dynasty: Qi rides the wind and scatters, but is retained when encountering water.
Historically, Feng Shui was widely used to orient buildings—often spiritually significant structures such as tombs, but also dwellings and other structures—in an auspicious manner. Depending on the particular style of Feng Shui being used, an auspicious site could be determined by reference to local features such as bodies of water, stars, or a compass.
Archaeological discoveries from Neolithic China and the literature of ancient China together give us an idea of the origins of Feng Shui techniques. The concept Yin and Yang plays a key role in the nature of Feng Shui. Yin is characterized as slow, soft, yielding, diffuse, cold, wet, and is associated with water, earth, the moon, femininity and nighttime. Yang, by contrast, is fast, hard, solid, focused, hot, dry, or aggressive, and is associated with fire, sky, the sun, masculinity and daytime. In premodern China, Yin Feng Shui (for tombs) had as much importance as Yang Feng Shui (for homes). For both types one had to determine direction by observing the skies and to determine the Yin and Yang of the land.
Nowadays, a growing body of research exists on the traditional forms of Feng Shui used and taught in Asia. Landscape ecologists find traditional Feng Shui an interesting study. In many cases, the only remaining patches of old forest in Asia are "Feng Shui woods," often associated with cultural heritage, historical continuity, and the preservation of species. Some researchers interpret the presence of these woods as indicators that the "healthy homes," sustainability and environmental components of ancient Feng Shui should not be easily dismissed.