This document discusses different types of Hatha yoga, including their history, founders, and key aspects. It summarizes Chaturanga yoga founded by Swami Swatmarama, which introduced 15 asanas and 8 types of pranayama. It also describes Saptanga or Ghatastha yoga from the Gheranda Samhita text focusing on purification and other practices. Iyengar yoga founded by BKS Iyengar is outlined, emphasizing proper alignment and use of props. Bikram yoga's 26 pose sequence in a hot room is explained. The health benefits of Iyengar yoga for conditions like low back pain and cardiovascular risks are highlighted based on various studies.