Reiki is a type of energy healing* in which Universal Life Force energy, "Ki" (also known as "chi" or "prana"), is channeled for the purpose of balancing, relaxation, and healing. It is similar to spiritual healing and advanced Chi Kung (Qi Gong) energy projection. Like some other forms of alternative healing such as acupuncture and accupressure, it involves encouraging the flow of the recipient's personal energy to release energy blockages, but it also involves the channeling of energy at different frequencies. The Reiki practitioner channels universal energy, like a conduit, into the recipient by placing hands lightly on or slightly above the recipient's affected area or energy center. Unlike Qi Gong, however, the practitioner does not use their own personal energy reserves and therefore does not get depleted while giving Reiki.
Through Reiki, one can heal on the spiritual and emotional levels as well as the physical as Reiki goes where it is needed in order to create energetic balance.
Reiki is not massage. Reiki sessions do not involve physical manipulation of muscle or tissues and a recipient does not remove clothing. An entire Reiki session can be conducted without physical contact with the sender hovering hands a few inches above the recipient or even at great distances since Reiki is energy and not limited by time and space.