In the Taoist tradition, dating from approximately 3000 B.C., the accumulated information and related practices are collected under the general heading of Chi Kung (or Chi Gung). This title means "Excellence of Energy" or the skill of governing one's life force.
As one might assume, recognizing the length of time involved (5000 years), there is an extrordinary range of exercises and practices contained under this heading. Some are stretching and limbering, some are primarily breath oriented, some are very quiet and meditative. But underlying all of these very diverse practices is the unifying element that they are dedicated to enhance the energetic level, the Chi, as their primary goal.
Quite frequently people ask me what the relationship between T'ai Chi Ch'uan and Chi Kung is. My answer is usually that good T'ai Chi is Chi Kung in that it too is primarily energetic in nature and is dedicated to the balancing, strengthening, and circulating of the Chi. But there are a few differences between the two. First, T'ai Chi Ch'uan carries with it the unmistakeable influence of its traditional use as a martial art, while Chi Kung was practiced exclusively for its health and spiritual benefits. Secondly, as is the case in all Chinese medicine, there is the distinction between that which is a specific medicinal remedy and that which is considered a tonic. Many Chi Kung exercises are very specific in that they address particular systems, be they energetic or physical, and their related diseases or imbalances. T'ai Chi rather falls under the heading of a tonic which is defined as "that which nurtures the whole".
When I was in China I was taught by my teachers that it was considered good procedure for a doctor to use Chi Kung exercises to help a person get to the point where they could then do T'ai Chi practice, and to view T'ai Chi as the ultimate health maintenance system. Now this is not to negate the importance of Chi Kung, such as standing practice, as a powerfull meditative tool for personal growth and a developer of specific qualities such as rooting. Certainly in the repertoire of the student of Internal practices there should be room and usage of a blend of T'ai Chi and Chi Kung, for really, T'ai Chi is Chi Kung, and Chi Kung is T'ai Chi.
