The word Reiki is made of two Japanese words - Rei which means "God's Wisdom or the Higher Power" and Ki which is "life force energy". So Reiki is actually "spiritually guided life force energy." 

Reiki is a very specific form of energy healing, in which hands are placed just off the body or lightly touching the body, as in “laying on of hands.” Reiki can also be done “long-distance,” as a form of prayer. According to many versions of its origin, Dr Mikao Usui, a Japanese seeker of spiritual truths, brought the Reiki method of healing into human awareness in 1922 after a deep spiritual experience. 

In a Reiki session, the practitioner transmits universal life force energy to the client through the hands. Reiki brings deep relaxation, assists in healing of the body, reduced pain, and helps you connect into higher wisdom and to come into connections with self.