(adapted from The Eight Limbs , The Core of Yoga by William J.D. Doran)
The practice of yoga is an art and science dedicated to creating union between body, mind and spirit. Its objective is to assist the practitioner in using the breath and body to foster an awareness of ourselves as individuals intimately connected to the unified whole of creation. It is about creating balance and equanimity to live in peace, good health and harmony with the greater whole. Patanjali’s eight step process to do this is known as the Eight limbs of Yoga. They are summarized below:
Yamas – Morality. Yamas are precepts for how we should treat others. They include: Ahimsa, compassion for all living things; Satya, commitment to truthfulness; Asteya, non-stealing; Brahmacharya, sense control and responsible behavior (mostly from a sexual conduct perspective); and Aparigraha, neutralizing the desire to acquire and hoard wealth.
Niyamas – Personal Observances. Niyamas are principles that for adopting a healthy attitude toward ourselves. Niyamas include: Sauca, purity or cleanliness; Santosa, contentment; Tapas, disciplined use of our energy; Svadhyaya, self inquiry; and Isvarapranidhana, celebration of the spiritual.
Asanas – Physical Postures. The practice of moving the body into postures has widespread benefits; such as improved health, strength, balance and flexibility. On a deeper level asana, which means “staying” or “abiding” in Sanskrit, is used as a tool to calm the mind and prepare for meditation.
Pranayama – Breath and Energy Control. Pranayama is the measuring, control, and directing of the breath and prana (energy). When breath and prana are controlled, then perfect relaxation and balance of body activities are realized. Proper, rhythmic patterns of slow deep breathing strengthen the respiratory system, soothe the nervous system, and reduce craving. As desires and cravings diminish, the mind is set free and becomes a fit vehicle for concentration.
Pratyahara – Sense Withdrawal. Pratyahara means withdrawal of the senses from attachment to external objects. It can then be seen as the practice of non-attachment to sensorial distractions as we constantly return to the path of self realization and achievement of internal peace. Much of our emotional imbalance is of our own creation. A person who is influenced by outside events and sensations can never achieve inner peace and tranquility. They waste mental and physical energy trying to suppress unwanted sensations or to heighten other sensations. This will eventually result in a physical or mental imbalance, and will, in most instances, result in illness.
Dharana – Concentration. In Dharana we focus the mind on one object and thereby steady it or quiet it as other activities of the mind fall away.
Dhyana – Meditation. Dhyana is perfect contemplation. It involves concentration upon a single point of focus with the intention of knowing the truth about it. During Dhyana, the consciousness is further unified by gaining clear insight into the distinctions between objects and subtle layers of perception. “We learn to differentiate between the mind of the perceiver, the means of perception, and the objects perceived, between words, their meanings, and ideas, and between all the levels of evolution of nature.
Samadhi – Union. Samadhi means “to bring together, to merge.” In the state of Samadhi the body and senses are at rest, as if asleep, yet the faculty of mind and reason are alert, as if awake; one goes beyond consciousness. During Samadhi, we realize what it is to be an identity without differences, and how a liberated soul can enjoy pure awareness of this pure identity. The conscious mind drops back into that unconscious oblivion from which it first emerged. Thus, Samadhi refers to union or true Yoga.
For a really good and complete explanation of the 8 Limbs I encourage you to read William Dorans’ work at http://www.expressionsofspirit.com/yoga/eight-limbs.htm.