Tai Chi and Yoga teach balance, stretching, toning; awakening to an awareness and flow of Energy, Qi, Chi, Prana. Qigong, Tai Chi, Yoga have developed over hundreds of years. Qigong and Yoga embody a way of living and both have developed over hundreds of years. Qigong and Yoga moves are designed to coordinate body movements and the breath. They are meditative practices which develop flexibility, strength, coordination, balance and so much more. These ancient practices trace their roots to the same Qi beginnings of those who went inward and sensed the energy within the body.
Qigong evolved in China, it is an older ancestor to Tai Chi. Long Form Tai Chi involves specific moves done together as one continuous flow practice. Short Form Tai Chi involves a shorter Flow series of moves repeated in different directions. Tao Yin Yoga is an arm of Qigong. Yoga evolved in India and involves several paths to wholeness. Today there are many manifestations of traditional Yoga. Most studios teach a modified form of Hatha Yoga. Check out the teacher and class to see if their technique is right for you.
When I was doing my Yoga teacher training at the Himalayan Institute (then in suburbs of Chicago) we lived a yogi lifestyle, what is called clean living today. Although not much is spoken about the strict rules and recommendations traditionally imposed on practitioners, there is wisdom and healing in that holistic lifestyle.