Young Sport Girl In Tight Yoga Pants

Hatha Yoga is a particular system of Yoga described by Yogi Swatmarama, compiler of the Hatha Yoga Pradipika in 15th century India. Hatha Yoga differs substantially from the Raja Yoga of Patanjali in that it focuses on "shatkarma," the purification of the physical body as leading to the purification of the mind ("ha"), and "prana," or vital energy (tha). Compared to the seated asana, or sitting meditation posture, of Patanjali's Raja yoga, it marks the development of asanas (plural) into the full body 'postures' now in popular usage and, along with its many modern variations, is the style that many people associate with the word "Yoga" today.
Modern, Westernised Yoga
In the West, the term "yoga" is typically associated with Hatha Yoga and its asanas (postures) or as a form of exercise.