阴 (Yin) is a fundamental concept in Chinese philosophy, particularly in Taoism and Confucianism. It represents the passive, receptive, and nurturing aspects of existence. Yin is often associated with qualities such as darkness, femininity, coldness, and stillness. It complements its counterpart, 阳 (Yang), which embodies active, bright, and dynamic characteristics. In the Yin-Yang symbol, Yin is depicted as the black swirl, illustrating the balance between these two forces. Together, Yin and Yang illustrate the interconnectedness of opposites in the universe, emphasizing that both are essential for harmony and balance in life.