The Different Ashtanga Series of Asanas

There are 3 main series of Ashtanga Yoga
and then the Advanced Series is divided into A, B, C, D.
Here's a little insight into the differences and
the reasons for the series.

Personally I always find Gerald's explanations fascinating
and his recounting of what Sri K Pattabhi Jois
taught him from 1991 - 1998.

Yoga Chikitsa - Primary Series

Nadi Shodhana - Intermediate Series

Sthira Bhaga - Advanced Series