Prana is the Sanskrit word for “vital life”. Similar to the Chinese notion of qi, prana is the notion of a vital, life-sustaining force of living beings and vital energy. Prana is a central concept in Ayurveda and Yoga, where it is believed to flow through a network of fine subtle channels called nadis. Its most subtle material form is the breath, but it is also to be found in the blood, and its most concentrated form is semen in men and vaginal fluid in women.

Prana was first expounded in the Upanishads, where it is part of the worldly, physical realm, sustaining the body and the mother of thought and thus also of the mind. Prana suffuses all living forms. In the Ayurveda, the Sun and sunshine are held to be a source of prana.

There are five pranas or vital currents in the Hindu system:
Prāṇa : Responsible for the beating of the heart and breathing. Prana enters the body through the breath and is sent to every cell through the circulatory system.
Apāna : Responsible for the elimination of waste products from the body through the lungs and excretory systems.
Uḍāna : Responsible for producing sounds through the vocal apparatus, as in speaking, singing, laughing, and crying. Also it represents the conscious energy required to produce the vocal sounds corresponding to the intent of the being. Hence Samyama on udana gives the higher centers total control over the body.
Samāna : Responsible for the digestion of food and cell metabolism (i.e. the repair and manufacture of new cells and growth). Samana also includes the heat regulating processes of the body. Auras are projections of this current. By meditational practices one can see auras of light around every being. Yogis who do special practise on samana can produce a blazing aura at will.[citation needed]
Vyāna : Responsible for the expansion and contraction processes of the body, e.g. the voluntary muscular system.

Pranayama is the practice in which the control of prana is achieved (initially) from the control of one’s breathing. According to Yogic philosophy the breath, or air, is merely a gateway to the world of prana and its manifestation in the body.

enjoy. and remember to BREATHE.