There are several Reiki symbols but most Reiki modalities use just four. Symbols are thought to possess a unique vibrational energy that helps facilitate the Reiki treatment. When they first were discovered and introduced to the Reiki practice, the symbols did not have names. They were simply called by numbers, from one to four. However, since each one of them conveys a specific purpose, they were given names.
The first symbol is called Cho Ku Rei and it is considered the Power Symbol. This means that during Reiki treatment the power of the universe is called upon to aid in the healing. Its literary translation is "place all the power of the universe right here." Through this symbol, the Reiki Master is able to draw energy from the source and then he can focus on where he wants it to go.
This power symbol can be used to cleanse negative energies, to invoke spiritual protection, for treatment directed to one specific spot or organ, and to help in manifesting desires. It is also used to seal the energies of the other three symbols and even to make them more powerful. For this reason, this symbol is used at the end of the treatment so as to give it a golden seal.
The second symbol is called Sei Hei Ki, is the Mental & Emotional symbol. As is name implies it, this symbol is used to help those who are afflicted by emotional pain and/or mental turmoil.
The literal translation of this symbol means "God and Humanity Are One." It is believed that this symbol helps activate the Kundalini, a corporeal energy located in the base of the spine. This energy also awakens during yoga and meditation creating balance between left and right hemispheres of the brain. This brings harmony, peace, and a sense of expanded consciousness. It also aids in the cleansing process, improves memory, clears energy blockages and aligns the chakras. It also provides psychic protection and eliminates negative vibrations.
The third symbol is called Hon Sha Ze Sho Nen which translates into "Distant Symbol". As the meaning implies, this symbol is used for distance healing. The symbol enables the Reiki channel to open and deliver the Reiki at a distance, and even send it to the past or the future.
This symbol represents a combination of the five kanji or Japanese characters meaning: source, being, just, certainty and thought. The symbol also represents a Buddhist chant for right consciousness as the root of everything.
The fourth symbol is known as Dai Ko Myo and this is used to initiate the student to the awareness of Reiki degrees. This is considered to be the most powerful symbol and can only be used by Reiki Masters. This is why this symbol is not introduced until Level Three training.