What do you mean by yin and yang?

Yin Yao and Yang Yao are terms in the eight diagrams, which are: the root of the stem is frightened and lost from the Kundui, representing the lightning, wind and fire in Tianshui Mountain, which are represented by the two smallest symbols, Yin Yao and Yang Yao, respectively. Yin Yao is two short horizontal lines, while Yang Yao is.