Ashtanga can refer to both a system of Asana (poses) popularized by the late Sri K. Pattabhi Jois and an 8-limb path towards realization.
The 8 limbs of Ashtanga Yoga are:
Yama [moral codes, restraints]
Niyama [self-purification and study, observances]
Asana [posture]
Pranayama [breath control]
Pratyahara [sense control]
Dharana [concentration]
Dhyana [meditation]
Samadhi [realization]
The physical postures (Asanas) of Ashtanga are most easily understood as a form of eastern calisthenics which make the body strong, flexible and coordinated. The system of postures also helps to purify the body and calm the mind.
Although Asana is the third limb in Ashtanga yoga, it is usually taught first in the system (especially in the west). Through the practice of Asana, the doorway is opened towards development of the other limbs.
Dr. K.L. Shankaranarayana Jois explains, “Limbs [of Ashtanga] are not steps. If they were steps, we would take them sequentially. Instead, they are like the limbs of our body. They need to cooperate and work together. As we rehabilitate ourselves, we need to improve our proficiency in all limbs simultaneously."
