Kundalini by Golden Totem by Forrest Darden

According to well-known teacher and translator Eknath Easwaran, kundalini means "the coiled power," a force which ordinarily rests at the base of the spine, described as being coiled there like a serpent. Through meditation, and various esoteric practices, such as Kundalini Yoga, Sahaja Yoga, and Kriya Yoga, the kundalini is awakened, and can rise up from the muladhara chakra through the central nadi, called sushumna, inside or alongside the spine and reaches the top of the head. The progress of kundalini through the different chakras leads to different levels of awakening and mystical experience, until the kundalini finally reaches the top of the head, Sahasrara or crown chakra, producing an extremely profound mystical experience.
A number of descriptions exist that attempt to describe exactly what the kundalini experience is:
Sri Ramana Maharshi mentioned that the kundalini energy is nothing but the natural energy of the Self, where Self is the universal consciousness (Paramatma) present in every being, and that the individual mind of thoughts cloaks this natural energy from unadulterated expression. Advaita teaches that Self-realization, enlightenment, God-consciousness, nirvana. But, initial kundalini awakening is just the beginning of actual spiritual experience. Self-inquiry meditation is considered a very natural and simple means of reaching this goal.