Hatha Yoga

Its a branch of Yoga.

Haṭha Ratnāvalī - a Haṭha yoga text written in the 17th century by Srinivasa.
 It is one of the first texts to name 84 asanas,

Three major surviving classical treatises on hatha yoga

1. The  Shiva Samhita
2. Gheranda Samhita
3. Hatha Yoga Pradipika.

Techniques consists of

1. Satkarmas - Purification Techniques
2. Asanas
3. Mudras
4. Pranayama

Almost all hathayogic texts belong to the Nath siddhas

The six purifications in Hathya Yoga

• Netī, a nasal wash. This is the practice of using a neti pot to cleanse the nasal passages . A basic neti wash consists of purified water and non-iodized salt, to create a gentle saline solution
• Dhautī the cleansing of the whole digestive tract.
• Naulī a self-administered abdominal massage, using only the muscles of the abdominal wall. The practitioner stands with the feet about hip width apart, hands on knees, and body at about a 45-degree angle. The core is rotated internally by moving the abdominal muscles alternately in a clockwise, then in a counterclockwise direction.
• Basti, a colonic irrigation.
• Kapālabhātī a skull polishing, and is a pranayama practice intended to energize and balance the nadis, and the chakras. Specifically, it is a sharp, short outbreath, followed by a relaxation of the core that allows the body to inhale on its own.
• Trāṭaka, gazing at a fixed point such as a black spot or a candle flame.