Chakra is a Sanskrit word meaning "wheel", appropriate because of the rotation of energy characteristic of a chakra. Technically the term refers to one of seven centers located in the etheric body, although it is also associated with points in the hands, feet and above the physical head, depending on the origin of the system. These centers allow energy (prana, chi)  from the etheric, spiritual and mental planes to flow through to the physical, each vibrating at a distinct frequency and emitting a color. Much as the visible light spectrum reveals the frequency of light waves, the chakras show the color of energy with red being the slowest vibration and violet being the highest in the traditional chakra system.

Keith Sherwood, in his book "The Art of Spiritual Healing" describes a chakra as a funnel, with the larger end on the surface of the etheric body. As the energy whirls into the small end of the funnel, sometimes blockages occur. Energy from the higher planes becomes blocked, unable to reach the physical plane resulting in something much like what happens when blood circulation cannot reach an organ or extremity. Depending on the severity of the blockage, the lower bodies develop emotional and even physical "dis-ease".

A spiritual healer observes these imbalances, hopefully before they become manifest on the lower planes, and helps to unblock the flow of energy and restore balance to the "patient".  Keeping the chakras balanced and fully open helps heal and prevent "dis-ease" on any plane and often prevents physical manifestation in the form of mental and physical illness. Many healers have specific programs targeting the chakras as a form of preventative medicine in addition to facilitating spiritual growth. 

Here is a brief, basic discussion of the individual chakras.

• The chakras are numbered, beginning with  the lowest vibration as the first, or root, chakra. Located at the base of the spine, the first chakra is associated with the color red energy is tied to the element of earth, grounding us and connecting us to the physical plane. Glandular system: gonads. Statement: I exist.
• The second chakra, or the sacral chakra, sits in the area of the reproductive organs and vibrates to the color orange. The sacral chakra controls emotions and sexuality. Glandular system: adrenal. Statement: I feel.
• The solar plexus chakra, or third chakra, is tied to the color yellow and is located just below the diaphragm. This chakra deals with intellect and ego. Glandular system: pancreas. Statement: I think
• The heart chakra, linked to the color green, sits at number four. Controls  love and relationships, especially "agape" or divine love and is located, of course, in the chest. Glandular system: lymphatic. Statement: I love.
• The throat chakra at number five radiates blue and holds sway over expression, helping to transmit the voice of the creative soul to the physical world. Glandular system: thyroid.  Statement: I speak.
• The sixth or brow chakra sits between and slightly above the eyes. Radiating indigo, it controls internal vision, intuition and self-realizations. Glandular system: pituitary. Statement: I see.
• Directly atop the head lies the seventh, or crown, chakra. Corresponding to the highest vibrations, the crown chakra vibrates to the color purple, and controls integration of the conscious and sub-consious minds. Glandular system: pineal. Statement: I know.