BKS Iyengar (1918 - 2014) systematised over 200 classical asanas and many pranayama techniques. In his system emphasis is placed on precise alignment in the postures. Use is made of props such as belts, blocks, bricks, and blankets in order that students of any level can work safely and effectively within the asanas. It is one of the most practiced forms of yoga worldwide.
Once a student is stable in their postural practice observation of the breath is introduced, initially in savasana (relaxation), which leads on to pranayama.
The benefits of regular practice can include enhanced flexibility, strength, balance, and coordination, as well as improved mental clarity and emotional stability.