Hatha yoga is a branch of yoga. The word haṭha literally means "force" and thus alludes to a system of physical techniques.
In India hatha yoga is associated in popular tradition with the 'jogis' of the Natha Sampradaya through its mythical founder Matsyendranath. Matsyendranath, also known as Minanath or Minapa in Tibet, is celebrated as a saint in both Buddhist and Hindu tantric and hatha yoga schools. James Mallinson associates hatha yoga more closely with the Dashanami Sampradaya and the mystical figure of Dattatreya, who is also worshipped by the Nathas.According to the Dattatreya Yoga Śastra, there are two forms of hatha yoga: one practiced by Yajñavalkya consisting of the eight limbs of ashtanga yoga and another practiced by Kapila consisting of eight mudras. Currently the oldest dated text to describe hatha yoga, the Amṛtasiddhi, comes from a tantric Buddhist milieu.The oldest texts to use the actual verbiage of hatha are also Vajrayana Buddhist.
In the 20th century, hatha yoga, particularly asanas (the physical postures), became popular throughout the world as a form of physical exercise, and is now colloquially termed as simply "yoga".