Haṭha yoga is a branch of yoga. The Sanskrit word Haṭha literally means “force” and thus alludes to a system of physical techniques. In India, haṭha yoga is associated traditionally with the Yogis of the Natha Sampradaya through its traditional founder Matsyendranath. Almost all Hatha yogic texts belong to the Nath Siddhas, and the important ones are credited to Matsyendranath’s disciple, Gorakhnath or Gorakshanath. Matsyendranath, also known as Minanath or Minapa in Tibet, is celebrated as a saint in both Hindu and Buddhist tantric and haṭha yoga schools. However, James Mallinson associates haṭha yoga with the Dashanami Sampradaya and the mystical figure of Dattatreya. According to the Dattatreya Yoga Śastra, there are two forms of haṭha yoga: one practiced by Yajñavalkya consisting of the eight limbs of ashtanga yoga and another practiced by Kapila consisting of eight mudras.
Hatha Yoga Today
In the 20th century, a development of haṭha yoga, focusing particularly on asanas (the physical postures), became popular throughout the world as a form of physical exercise. This modern form of yoga is now widely known simply as “yoga”. 
Hatha yoga is the branch of yoga that typically comes to mind when you think of yoga in general terms. The practice involves breath, body, and mind, and classes are usually 45 to 90 minutes of breathing, yoga poses, and meditation.
Today, roughly one in seven Americans practice yoga due to its mind-body wellness and health benefits. Research shows hatha yoga helps to relieve stress, support healthy habits, improve emotional health, ease back and arthritis pain, and even help people quit smoking.
History
Again, in Sanskrit, Hatha means force. Hatha yoga breathing techniques can be traced back to the 1st Century in both Buddhist and Hindu texts, but it was another 1,000 years before the use of yoga postures, or asanas, and breath control was recorded as a way to enhance vital energy.
The oldest dated text to describe Haṭha yoga was the 11th-century CE Amṛtasiddhi from a tantric Buddhist milieu. The oldest texts to use the terminology of Hatha are also Vajrayana Buddhist. Later haṭha yoga texts adopt the practices of haṭha yoga mudras into a Saiva system, melding it with Layayoga methods which focus on the raising of kuṇḍalinī through energy channels and chakras.
Classical Hatha yoga was developed in the 15th century and included guidance for the proper setting of yoga, asanas, pranayama or breathing exercises, mudras or hand gestures, and meditation for personal spiritual growth.