Taking Ashtanga yoga as the standard we have to understand the eight limbs or steps in aid of yoga. They are as follows:

(1) Yama: This is the initial step. The trainee (sadhaka) in yoga has to practice certain negative virtues like abstention from evil thinking and evil doing.

(2) Niyama: In this step the trainee has to develop and practice positive virtues and follow certain moral codes and standards of conduct.

(3) Asana: In this step the trainee has to improve his health and physical fitness. The body is the temple of God and also the vehicle of Karma. It is therefore the duty of every one to keep his body clean and fit. Asana comprises various postures of sitting and physical twists and bends which the trainee is expected to do every day with a view to keep his body in a healthy condition. Ill health and practice of yoga cannot go together.

Asana exercise is different from other forms of exercise like running, jumping, weight lifting and swimming where maximum energy is spent with minimum benefit. In the asana exercise there is not much scope for the play of ego and maximum benefit is obtained with minimum energy spent. Asana exercises stimulate glands and internal organs. They are capable of curing many bodily ailments which stand as impediments in the practice of yoga. The efficacy of Asana exercises is being recognized in the western countries and America for maintaining health and physical fitness.

(4) Pranayama: This is a step as the name indicates of storing prana or vital energy which is the pivot of the training in yoga. Prana is the life principle in motion as the Holy breath of life acting on the five sensory organs bringing out the impressions of the phenomenal world.

Sage Thiruvalluvar says in his 'Kural' "They gain the world who grasp and tell of taste, sight, hearing, touch and smell." The phenomenal world is a concomitance of these senses and is sustained by the lower side of the mind or ego of every individual. In course of time he becomes aware of that fact that his senses are gaining for him only ephemeral sensations and not lasting happiness. He finds himself a victim in the meshes of his own web or mental involvements and wants to extricate himself This extrication, popularly known as Moksham, is possible only by undoing his own involvements with his own senses. In a very cryptic manner Bhagvan Satya Sai Baba has described Moksham as Moha Kshayam which means ending all desires.

Yama, Niyama and Asana are three preparatory steps to regulate the external sadhana (training) of the sadhaka (student). Pranayama is a transitory step to get on to other steps regulating the internal sadhana or exercise of the student of yoga.

(5) Pratyahara: With this step the inner training of the sadhaka begins. He practices the retracting of the sense organs from the objects of senses.

(6) Dharana: This is the practice of concentration. The trainee pins his thought on any noble or spiritual concept to gain control over his mind.

(7) Dhayana: This is the practice of meditation by the sadhaka fixing his attention to his mind centre located inside the middle of his brows. The great Buddhist monk Bodhi Dharma of Conjeevaram commended this practice and carried it to China where it came to be known as Chan. From China it spread to Korea and thence to Japan where it came to be known as Zen.

(8) Samadhi: This is the highest stage of ecstatic consciousness in the yoga practice. The trainee attains perfect stillness of thought in which the sense of individuality or ego is extinguished. At this stage the sadhaka is held to win various miraculous powers called Vibuthi. The sadhaka becomes a siddha or paramahamsa who is superior to an ascetic and even to men of knowledge and action, according to Bhagavat Githa.