Prāṇa

Prāṇa (प्राण) is the Sanskrit word for "vital life" (from the root prā). In Vedantic philosophy, prana is the notion of a vital, life-sustaining force of living beings and vital energy, comparable to the Chinese notion of Qi. In human beings, it flows through a network of fine subtle channels called nāḍis. In the Theosophical literature prāṇa is the third (sometimes second) principle of human beings, usually referred as "life principle" or "vital principle."