What is Five Elements?

The Five Elements are Wood (木), Fire (火), Earth (土), Metal (金), and Water (水) — the five phases that describe cyclical processes in Chinese cosmology. They interact through generation (生) and control (克) cycles. In Liu Yao, each line's element determines its Six Relative role and its strength relative to the casting date. In the almanac, elemental interactions between day stems and activity categories govern auspiciousness.

Source: Shangshu Hong Fan (尚書·洪範); Xi Ci Zhuan (繫辭傳)