prana is a core concept in the indian system. yoga, ayurveda, tantra and philosophy talk very exhaustively about prana. prana is basically the life force, externally expressed as breath. in subtle form prana permeates everything, both living and non- living. in this phenomenal world, prana is constantly moving and sustaining all types of existence. this prana is called chi in chinese medicine and ki in the japanese system. it is the belief in the indian system that the proper flow of prana ensures good heal