Hatha Yoga is what most people think of when they hear the word "yoga". Hatha yoga is the practice of asana, or physical postures, and it is used to balance and purify the body and mind in preparation for more advanced practices.
In addition to the asanas that many people are familiar with, Hatha Yoga also includes shatkarmas, or cleansing practices.
The practices of mudras and bandhas are also a part of Hatha Yoga. Mudras are a combination of subtle physical movements or positions done with the hands, head or whole body. They alter the mood, perception and deepen awareness and concentration. The aim is to link the neo-cortex with the limbic and instinctual structures of the brain, bringing the practitioner out of unconscious habitual patterns and emotional reactions and into more conscious control.
Bandhas were originally understood as types of mudras, and they are often used in conjunction with mudra as well as pranayama. Bandha means to "hold", "tighten" or "lock" in Sanskrit, which is an apt literal description of how to perform a bandha. The intention of bandha is to hold prana (energy) in a specific area in order to then redirect the movement of prana for spiritual awakening.