The Serpentine Power is called Kundalini-Sakti. Its a spiral-like working in the body of the Yogi developing the power in himself. It is an electric fiery occult power, the mighty pristine force underlying all organic and inorganic matter. The Yoga which treats of this Kundalini-Sakti is called Kundalini-Yoga and Hatha Yoga is Kundalini Yoga.
Practical Lessons in Yoga
by Swami Sivananda Saraswati