The term Jing is generally translated as Essence. It refers to a refined substance through the set of bodily processes, and stored in the Kidneys as the material support of life.
It is divided into three "types" to slightly differentiate its origin, although essentially they are the same.
Essence
The three types of essence are:
It is impossible to separate the essence, although it is possible through proper diagnosis to determine the state of each one in order to address them in treatment.