Pralaya

(Sanskrit) A cosmic period of repose or rest.

A Sanskrit word, formed of pra and laya. Pra, means “forwards” or “progression,” Laya, from the root li, which means “to dissolve,” “to melt away,” “to liquefy”.

Prana

प्राण Prana: breath of life, breath, filled, old, full, ancient, spirit, vitality, energy, wind, spirit, respiration, spirit identified with the totality of dreaming spirits, poetical inspiration, vigour, life, power, air inhaled, vital organ, vital air, myrrh

Pranayama

Pranayama commonly interpreted as breath control or breathing exercises. It is really much more powerful than that; as Vivekananda said, breathing has very little to do with it. Pranayama is about controlling energy. Prana is life force, the vital energy; it is the root energy of being alive. When you learn Pranayama, you learn to control that energy and utilize it in your spiritual practice. 

Pranayama प्राणायाम

Sanskrit प्राणायाम for ‘restraint (ayama) of energy, life force (prana).’ A type of breathing exercise which transforms the life force (sexual energy) of the practitioner.

Prana is a Sanskrit word which means “energy,” and Yama refers to breathing or respiration.