Moxibustion is burning moxa (the herb mugwort, Artemesia vulgaris) on or above the skin (or on a needle) to warm the channels, strengthen the body, and promote circulation. Moxa comes in several forms, including a raw form (which can be shaped into a cone or ball) and a stick form which is used above a certain acupuncture point or area. When used "on the skin", a protective barrier is used between the skin and moxa to prevent discomfort.
Moxa has a warm, penetrating nature making it perfect for increasing circulation and improving health. This means it's great for achy, painful joints and to improve the immune function. Moxa is also good for digestive problems, diarrhea and to assist in getting rid of (as well as prevent!) the common cold.