So what is Qi-Gong? Everybody's heard of yoga, most people have heard of Tai Chi, and many people are now starting to hear about Qi-Gong (Chee-Gong). What is it? It's very complicated and therefore difficult to explain briefly. It has to do with many eastern medicine concepts such as chi-flow, meridians, gong, chakras, the dantian center, yin & yang, etc... Suffice it to say, from a purely health & fitness perspective Qi-Gong is an ancient energy-enhancement system that promotes longevity. All the elderly Chinese folks in parks in the morning waving their arms about are all doing some form of Tai Chi or Chi-Kung/Qi-Gong.
Chi could very roughly be explained as the electro-magnetic force-field, or energy blue-print, if you will, that holds the physical body's molecules in place. When a person dies, the chi body dissipates, and the physical body falls apart. It is the power of chi that allows a shoot of grass to break through a cement sidewalk. Advanced karate practitioners enhance their chi in order to be able to smash cinder-blocks with the thin bones of their hands, elbows, and foreheads. Think about the physics involved in a stack of 10 cinder-blocks being smashed with the eggshell-like bone of the skull.
Chi is the life-force. Male athletes abstain from sex before their various events because one "Lovin' Spoonful" ("10-CC's") of male ejaculate is the life-force equivalent of an atomic bomb - it can hypothetically repopulate the entire planet. Athletes try to focus and avoid draining that energy to enhance their power. This is Chi.
"Gong", while related, is another form of energy altogether. However, the explanation of the energy "gong" is lengthy and would need a lot more space than a website for clarification. In a nutshell, Gong energy is used for Buddha-Body-Building. If you want to find out what that is, you can download the book "Zhuan Falun" by Li Hongzhi. A bonafide Qi-Gong practice is an enlightenment path and goes far beyond the realm of health & fitness, which again is why I can only teach the exercises of this system in service, and can't take money for it.