Hatha yoga is the most popular yoga. The word 'Hatha’ derives from Sanskrit. It consists of two words 'ha' and 'tha'. 'Ha' means sun and 'tha' means moon. Sun refers to male energy principle in the body, which is related to the flow of breath through the right nostril. Moon refers to the female energy principle. It is associated with the flow of breath through the left nostril. Hatha Yoga balances these two forces. It gives peace to mind and energy to the body. It is preparation on the yoga of meditation. Hatha yoga is great science. It awakes our energy and breath. It is a beautiful system for attaining perfect health. It has been practiced since 2500 BC. Lord Siva is the founder of hatha yoga. There were 84,000 asanas in the beginning. It has been reduced to 34 nowadays. These are considered as the most important and most useful for the human body. Goraksha Samhita, Hatha Yoga Pradipika, Kheranda Samhita and Siva Samhita are the most important tre...