The first two limbs of yoga are ethical and personal practices that form the moral foundation for everything else. The Yamas are five ethical restraints that govern how we interact with the world around us. Ahimsa teaches non-violence in thought, word, and action toward oneself and others, and is considered the most important of all the Yamas. Satya invites truthfulness, Asteya discourages stealing in all its forms, Brahmacharya calls for moderation and the wise stewardship of one's energy, and Aparigraha encourages non-possessiveness and freedom from greed.
The Niyamas, by contrast, are five personal observances that cultivate inner discipline and self-growth. Saucha promotes cleanliness in both the body and the mind, while Santosha nurtures contentment with what is. Tapas refers to the committed inner fire or discipline required to sustain practice through challenge, and Svadhyaya involves self-study and self-reflection through observation and the study of sacred texts. The fifth Niyama, Ishvara Pranidhana, is the practice of surrendering to a higher power or to the natural flow of life, releasing the ego's grip on outcomes.
Together, the Yamas and Niyamas are not mere rules but living principles. They shape a yogi's character both on and off the mat, providing the inner ground in which the physical and meditative practices of yoga can take root and flourish.