Chakra is the sanskrit word meaning "wheel".  The image shows the commonly referenced primary chakras. 

Spiritually speaking, a chakra is an energy focal point, related to specific areas such as communication, or knowing, or the energetic heart.  While definitions vary, most teachings focus on the seven primary etheric chakras.  Some associate chakras with colors, vibrations, musical tones, even physical glands.

How do you cleanse and rebalance a chakra?  Our natural state is a state of flow and balance, and our chakras flow and change all the time.  Sometimes we can feel 'stuck', or experience an unpleasant feeling or mood. Energy awareness techniques can be learned for higher awareness, and energy release techniques for clearing and rebalancing.

The primary chakras (top to bottom)

Crown: Knowing your information and answers
Brow: Seeing, processing.
Throat: Communication (internal dialog, communication with others)
Heart: Seat of the soul - compassion, affinity
Solar Plexus: Expression in the body of your spiritual self
Belly: Emotions, gender
Root: Basic physical needs

The hands and feet also contain chakras, and many minor chakras are found throughout the entire body.

How do you learn more about your chakras?  You can sign up for a reading, and ask specifically for a chakra or aura reading.