Acupuncture meridians.
There are 14 main meridians or channels in the body through which the life force, Qi, and Blood, flow to all parts of the body. If the Qi and Blood flow is normal then the body is healthy, if there is some disruption of this flow then disease can occur. Acupuncture points are located on these channels and can be used to regulate the amount of Qi and Blood flowing in the channels.
Imagine these channels or meridians carrying electricity to all parts of the body.
Acupuncture points can be thought of as the amplifiers that control the amount of electricity that will bring about the normal flow of Qi and Blood. In this way everything in the body is balanced.