It’s a tradition going back 10,000 years but more developed to a technical level with acupuncture in the last few hundred (I forget). It’s also related to Traditional Chinese Medicine which uses the principles in qigong and the I Ching (the book of changes, kind of sort a Chinese rune set but with more everything). It includes a cosmology and detailed energy working philosophy. Tai Chi Chuan is a Chinese martial art that incorporates energy working. It provides a complete system for all aspects of life.
I posted a list of good books of the subject here: