Gong (Kung) is the same as in Gong Fu, which simplified means work. Hence, Qigong (Chi Kung) means qi work; learning about it and doing it for many hours over long periods of time in order to develop it. How else could one become familiar with Qi, something that cannot be seen, smelt, tasted, heard or touched by most people. Something that has most principles and physical qualities that opposite those of this physical plane. However, after some initial instruction and work, one can begin to feel qi. Perhaps this is the main meaning of the first lines of the Tao Te Ching: "The Way that can be spoken of is not the constant Way."
With long periods of good instruction from a qualified Qigong Master, Qi can become a reality. It can be seen, smelt, tasted, heard and touched. These "Internal Senses" are developed as the practitioners base for further study and use of Qigong.