Prana is considered a form of cosmic energy and is meant to flow freely within the subtle, physical and causal bodies through energetic channels called nadis (flow, motion or vibration). These nadis which are considered from Tantric texts to populate the body with 72,000 paths and centralise at certain points in the body known as chakras. There are three main nadis that yogis refer to consisting of the sushumna, ida and pingala. The practice of yoga is a way to unblock the nadis and produce an open channel through the sushumna for kundalini (divine energy) to flow leading to moksha; liberation from suffering.
Swami Vivekananda describes Kundalini briefly in his book Raja Yoga as follows:c
According to the Yogis, there are two nerve currents in the spinal column, called Pingalâ and Idâ, and a hollow canal called Sushumnâ running through the spinal cord. At the lower end of the hollow canal is what the Yogis