Ashtanga yoga is named after the 8 limbs of yoga mentioned in the "Yoga Sutra of Patanjali". The 8 limbs represent (1) moral codes (yama), (2) self-purification and study (niyama), (3) posture (asana), (4) breath regulation (pranayama), (5) withdrawal from senses (pratyahara), (6) concentration (dharana), (7) meditation (dhyana) and (8) liberation (samadhi). It is a path towards Self discovery and a journey towards inner peace.
With respect to asana, Ashtanga yoga is a dynamic form of yoga with over 60 poses from the primary series; of which, some are taught during the beginner yoga class.