In Sanātana/Hindu, tantric/yogic traditions and other belief systems, chakras are points in the body where energy channels, called nadiis meet. Nadiis are channels through which the life force (prana), or vital energy moves. There are many Chakras in the human body according to the tantric texts, but there are seven chakras that are considered to be the most important ones.

Their name derives from the Sanskrit word for "wheel" or "turning", but in the yogic context a better translation of the word is "vortex" or "whirlpool".

The function of the Chakras is to spin and draw in this energy to keep the spiritual, mental, emotional and physical health of the body in balance.

You can sense an energetic imbalance among the Chakras as almost a continuous feeling of dissatisfaction. When the heart Chakra is agitated, people lose touch with feelings and sensations, and that breeds the sense of dissatisfaction. That leads to looking outside for fulfilment. When people live in their heads, feelings are secondary; they are interpretations of mental images that are fed back to the individual. When awareness is focused on memories of past experiences and mental verbalisations, the energy flow to the head Chakra increases and the energy flow to the heart Chakra lessens. Without nurturing feelings of the heart a subtle form of anxiety arises which results in the self reaching out for experience. When the throat Chakra settles and energy is distributed evenly between the head and the heart Chakras, one is able to truly contact one's senses and touch real feelings. READ MORE about Chakras on Wikipedia.