The word yoga means "union", referring to combining your mind with the physical body. You are practicing it to calm your mind, by holding a present focus and release any limitations in the body. Yoga can be practiced in different ways, ranging from a physical flow yoga with music to a sedentary breathing exercise in silence. An important factor in practice is the breathing, which allows the body to heal by a more energetic respiration. They talk, according to Patanjali in the Yoga Sutras, about the eightfold path that includes the wholeness of yoga.
Who can do yoga?
Everyone!!! Everyone who can breathe.