Yoga Nidra as practised around the world now was developed by Sri Swami Satyananda of the Bihar School of Yoga, from an advanced Tantric technique called nyasa.  During nyasa a yogi mentally touches various parts of his or her body with consciousness while repeating mantras.  When this is done in the prescribed manner the yogi is able to awaken subtle energy within the physical matter of the body.

The practice  connects you to your subconscious and unconscious minds.  The main aim of yoga nidra practice is the exploration of consciousness, with the ultimate aim of increasing self-awareness; but it has the side-effects of deep relaxation, rejuvenation, healing and increased inner strength.  The characteristic feature of Satyananda Yoga Nidra is the systematic rotation of consciousness in the body, and other stages that include settling, sankalpa (resolve), breath awareness, pairs of opposites, visualization and so on.  A practice is led...