What is Reiki energy?

Any creatures have strong will to survive.
For example, if we see plants we could see their strong vital force, we could also know the difference from two plants one was place under sufficient light from sun another was placed in the dark.
We could say our such vital force is consist of energy from outside.
What is energy outside? foods, water, air, lights and so on. We could survive with receiving these energy from outside.
We call these energy which makes us healthy and happy, "Reiki".
Therefore reiki exist in any part of the world or may be in any other galaxy, we also call reiki "Universal Energy".