One of the interesting parts of Chinese Medicine and Chinese culture is the Five Elements. At some point during the Han Dynasty (~200BC to ~200AD), the Five Elements were used to categorize and understand everything: people, buildings, cultures, astrology, food, medicines, you name it. I heard a story once that generals would send out spies to analyze the Elements of the enemy so that the weak Element could be exploited. True or not, it is fascinating how different they were compared to our culture which is obsessed with technology and a certain brand of science that requires a lot of money.
The Five Elements are not a stone age version of the periodic table, resulting in a kindergarten version of chemistry. The Five Elements symbolize the overall zeitgeist of a subject and represent a different kind of thinking. They originally come from the four seasons, but they add an additional energy. Wood is the first element, and it corresponds to Spring. Seen in people, it is shouting, youthfulness and a starting energy. Its emotion is anger.
The second element is Fire, and it corresponds to Summer. Seen in people, it is laughter, relationship, connection and a moving energy. Its emotion is joy.
The third element is Metal, and it corresponds to Autumn. Seen in people it is weeping, maturation, discernment and a declining energy. Its emotion is grief.
The fourth element is Water and it corresponds to Winter. Seen in people it is groaning, solitude, introspection and a hibernating energy. Its emotion is fear.
The fifth element is Earth. Earth is a centering energy, related to food and family. Seen in people it is nurturing, loyal and social. Its emotion is worry.
Looking at these as a system, they create a circle that needs to turn. Earth is in the center and the other four revolve around it. Wood is the starting energy of the cycle, Fire is the moving energy, Metal is the slowing energy, while Water is the stopping energy. Earth keeps them all together, like a family.
I hope this helps you understand this unique and useful system. Stay tuned for how to use it!