What is Reiki?  Quite literally it translates to "Spiritual / Heavenly Energy" - The Raining Energy. 
This isn't a form of forced / pushed healing - it is one which the body receiving the treatment (including on ourselves) chooses how much to receive and where to direct it. 
"It" is the same energy no matter what you call it.  Divine touch, laying on of Hands, Reiki.  It's being willing to be open to channeling Divine healing energy to another. So Reiki is a self guiding system of energy for the day to day practitioner.  By being the channel through which it enters another - it knows inately where healing/aide is needed and goes to that spot/issue. 
Reiki Masters or those who practice it in combination with other healing modalities may bring the focus into an area that they are working on to speed healing / recovery.

While your practitioner may use Reiki in combination with other techniques and services to enhance the overall healing and stress reducing effect of your session.
When we learn or are "attuned" to Reiki - it is done in 3 levels.
1. Work on self, pets and eventually those close to us (family and direct friends).
2. We become a basic practitioner - working with clients, family etc. 
3. Becoming the master.  This level bring the addition of working across time and space to fix the energy of events that have

Reiki 1

SHODEN: Becoming the Reed
Learning to be open to the flow of Reiki / Divine energy.
The work of the Self

reiki 2

Okuden
Exploring and learning the hidden or inner ways.  Working with self, animals, others. 

reiki 3

Shinpiden: The master way
Any Time and Space with Reiki.
The remote laying on of hands.

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