So what is feng shui and why is it so difficult to understand it? Well, for one, feng shui is a very, very old art and science. Its history goes back thousands of years. That is really, really old, which means really, really easy to misinterpret. Because feng shui is such an ancient body of knowledge, it has also been fully “steeped” in cultural stereotypes. This makes it very important to distinguish between the culturally specific expressions of energy and the very essence of any given form of energy.
The five elements can interact in any number of ways, some constructive and some destructive. In the constructive cycle, for example, water provides moisture for trees (wood) to grow; wood then becomes a fuel for fire; the residue of fire is ash or soil; the ash/soil is the essence of earth minerals that form metals; and as metal cool, they allow water to condense, completing the cycle. In a destructive cycle, on the other hand, metal can cut wood; and wood can grow over and consume soil.  
A grave at Puyang (around 4000 BC) that contains mosaics— actually a Chinese star map of the Dragon and Tiger asterisms and Beidou (the Big Dipper, Ladle or Bushel)— is oriented along a north–south axis.[6] The presence of both round and square shapes in the Puyang tomb, at Hongshan ceremonial centers and at the late Longshan settlement at Lutaigang,[7] suggests that gaitian cosmography (heaven-round, earth-square) existed in Chinese society long before it appeared in the Zhoubi Suanjing.[8]