Astanga is a system of yoga that was brought to the modern world by Sri. k. Pattabhi Jois. Each series is a set of sequence of asanas, always in the same order. It is typically fast-paced, vigorous and physically challenging.
The first series begins with 10 sun salutations (A and B), continues with a series of standing poses done on each side, and finishes with a set of inversions and seated poses, which are linked by a Vinyasa sequence.
Benefits: strength, flexibility, stress management and inner peace. Because the series is so demanding you will get really strong. There is no part of the body that doesn't work in this practice.