Within every living body, although on the subtle rather than the gross or physical level, there are said to be a series of energy fields or centres of consciousness, which in traditional Tantric teachings are called chakras ("wheels" , ) or padmas ("lotuses"). They are said to be located either along, or just in front of, the backbone, even though they may express themselves externally at points along the front of the body (navel, heart, throat, etc). Associated with the chakras is a latent subtle energy, called Kundalini in Shaktism, and tumo in Tibetan Buddhist Tantra.
Speculations and teachings concerning the chakras have occured independently in the religious, spiritual, yogic, and occult traditions of India, China, and the West. Although having certain basic points in common, these also differ in many details. So we have a number of different chakra-doctrines that have developed in different esoteric traditions to greater or lesser completeness.
 a note regarding pronounciation. It seems that just about everyone nowadays says "shar-kra". The origin of this particular pronounciation is unclear, but the fact is that the Sanskrit word cakra is - depending on the accent - either pronounced "cha-kra" with the "a"'s like the "u" in "but", or "cho-kro" with the "o"'s as in "box". So: "chakra", not "sharkra"
 The modern use of the term chakra - "wheel" - claims this is how they appearaer to yogic and clairvoyant perception, but there is no evidence that the tantrics considered or even experienced the chakras in this manner.
 Sometimes two lines of chakras are described - one for the front of the body and the other for the back. See Barbara Brennan's work in this respect.