Chakra means a wheel. There are six centres of spiritual consciousness represented as shadchakras which are supposed to be attached to the spinal chord and connected to various koshas (sheaths) through several nadis (channels of energy). But in fact these centres are in the subtle body (Sukshma sarira). The six chakras are Mooladhara, Svadhisthana, Manipura, Anahata, Vishudha and Ajna.