Internal Elixir (Nei Dan) focuses on building the energy from inside the body, stored like the battery of the body. It uses gentle movements to lead and manifest qi to flow along the meridians, then out through the internal organs and the whole body.

External Elixir (Wai Dan) uses more vigorous movements to build qi in the arms and legs. When enough qi is accumulated, it will flow thru the body's meridian system inwards to nourish the internal organs.