YIN is the Black Side with the White Dot and YANG is the White Side with the Black Dot. Picture the sun moving over a mountain and valley. Yin is the shady, dark area; Yang is the sunny, brightly lit area.  As the sun moves across the sky, they gradually trade places revealing what was obscured and obscuring what was revealed. YIN is characterized as slow, soft, yielding, diffuse, cold, wet and passive; it is associated with water, earth, the moon, femininity and nighttime.  YANG, by contrast is fast, hard, solid, focused, hot, dry and active; it is associated with fire, sky, the sun, masculinity and daytime.