Yin is the feminine, negative principle in Chinese philosophy. It’s associated with Earth and passivity.
Have you ever heard someone talk about balancing their yin and yang? Those are two contrasting aspects of Chinese philosophy. While yang is male, yin is female. Yin and yang both exist in everyone, which is why balancing them is considered important. Besides being associated with femaleness, yin also involves Earth, darkness, passiveness, and cold. Yin and yang are usually discussed together. The symbol of yin and yang is black and white, representing how the two principles complement each other.