Prana

Prana is the vital air or breath of the human body in Hinduism. It is also the vital, life-sustaining force of both the individual body and the universe. Its was first written about in the Upanishads. Prana is in all living forms, but is not itself the soul.
The word prana means "breath" in Sanskrit.
In yoga, prana is divided into different type. There are said to be five pranas or vital currents. They are called prana, apana, vyana, udana and samana.