Patanjali, the father of yoga, wrote the "yoga sutra", which endowed all the theories and knowledge of yoga, in this work, he explained the definition of yoga, yoga content, yoga to the internal changes of the body and so on. Before patanjali, yoga had a long practice period, but no one gave a systematic explanation of yoga, patanjali created a whole yoga system. Patanjali pointed out that yoga is not a theory, not exist and theory, it is more of a practice, if you want to become a real yoga person, not theoretical yoga, but practice yoga, so that you can really become a yoga person. Patanjali is clear about yoga's purpose: yoga teaches how to control the brain (CHITTA).