T’ai Chi, like Yoga, is technically not meditation but you are in a meditative state while performing it. Many people call it ‘Meditation in Motion. Like Yoga, T’ai Chi concentrates on improving the flow of life force through you using two either NeiGong or QiGong.
When done in a meditative state T’ai Chi helps improve the flow of energy (Chi or Qi) inside of you which then helps reduce tension and relax you.
As a meditation practice, the cultivation of calm and focus helps maintain your health and is performed as a type of martial art.
As a movement practice, T’ai Chi helps with responding to outside forces attacking you by performing the proper responses to the attacks for self-defense.