Chakra is the Sanskrit term meaning wheel or circle sometimes referring to the the wheel of life (Dharmachakra). The Hindu scriptures describes them intensively and are the base of the Vedic health system. It could be compared to the acupuncture point in the Chinese system. The principal ancient texts which treat of chakras are the 2 tantric texts: the Sat-Cakra-Nirupana, and the Padaka-Pancaka. But first references are found in the Upanishads. It describes a complete body system where energy go through these node in order to attain the different organs of the body to make it functioning. The Hindu scripture describes the system very well and it seems that they know what they are saying. Our modern society tried also to explain these energy nodes in modern terms. The Theosophical Society, for example, includes them in their belief system too. The chakras are the several nodes in the body by which the energy flows. They are said to be the point of interaction between the physical and mental nature of the person too.
Each chakra represents a particular consciousness state, at least for the eight principal tantric chakras. Also, a color is assigned to each of theses chakras. Furthermore, the chakras are said to be the centers of energy in the body and can be used as energy stock, principally the “solar plexus”. Chakras are the nodes in which the energy and feelings pass by. Chakra also represent a spiritual evolutionary process. Each chakra represents a certain point in the path to attain the highest spiritual state: the whole consciousness. The highest chakra being the one located on the top of the head. During a spiritual pursuit, the person will pass by each of these symbolic chakras. In fact, most western people believe that Hindu scripture talks only about these symbolic meanings and it has no relation to the body.
But, chakras have also been studied by some modern scientist and several people says that chakras could be the respective endocrine glands located at the exact body location that the Hindu scriptures said about the chakras. Furthermore, the endocrine glands, being the centers of the hormones generate the moods of the person and thus, its mental state. Physical state and mental state are link by these endocrine glands as the Hindu scripture said about the chakras. The modern thinking, being to materialist see only a gland while the Hinduism see a node.