The five elements (五行）in Chinese thought are fire (火）, earth（土）, metal（金）, water（水）, and wood （木）.  Rather than viewing the five elements as separate or competing systems, they should be seen as five phases in a cycle.  Each "gives birth to" another.  Each is born of another.  Each can destroy another.  And each can be destroyed by another.  The pattern of the five elements in a cycle, with a five-point star drawn between the opposing sides, indicates the way these inter-relationships flow.

Each of the five elements represents a phase in a cycle of being, analogous to the seasons within a year.  Fire represents summer, earth is the change of seasons, metal is autumn, water is winter, and wood is spring.  

The five elements are used in many aspects of Chinese thought, including Chinese medicine, martial arts, music, astrology, feng shui, and fortune telling.  The elements and the relationships between them comes up over and over again in varying aspects of Chinese thinking.