One of the five pranas of the body.
There are five basic manifestations of prana in the body. These pancha vayus – prana vayu, samana vayu, udana vayu, apana vayu, and vyana vayu – direct different aspects of the human mechanism. Through yogic practices like the Shakti Chalana Kriya, you can to take charge of the pancha vayus. If you gain mastery over these five vayus, you will be free from most ailments, particularly psychological ones. This is something that the world needs today.