Hatha Yoga
There are numerous schools of Hatha Yoga, and it is not uncommon for teachers to blend techniques from various schools to create their own approach to teaching. The differences between these forms of Hatha Yoga are usually about emphasis not the substance of the teaching. One may focus on coordinating movement and breathing, another may stress the strict alignment of the body, or the focus may be on holding each posture for a period of time.
Many of the best known teachers of Hatha Yoga that have developed a following in the West can trace their roots to the Indian Sanskrit teacher and scholar Krishnamacharya (1889-1989). A few of the most influential and popular teachers are: B.K.S. Iyengar, the founder of Iyengar Yoga; T.K.V. Desikachar (Krishnamacharya's son), who continues the tradition known as Viniyoga that he learned from his father; and Sri K. Pattabhi Jois, the developer of Ashtanga Yoga.
Someone new to yoga may want to try classes in different styles and with different teachers to find the one that is the best match.