The word yoga, among some of its definitions means “to enter”, “to gather”, “to join”, “to tie”, “to unite”, “to concentrate”, “to put under the yoke”, which in turn comes from the verb yuj- or yug and is associated with meditation practices. Casually the yoke is a wooden artifact, which joined two mules or two oxen, or a pair of animals that work together, as a team. That was use by merchants and farmers to carry out their work.
This comparison goes to the similarity of the subjugation over our ego. If we become regular practitioners of this discipline, yoga has a cleaning effect, purification, and the ability to remove those impurities that make up the darker traits of our personality, weakening and harming our will, which would be an impediment to the search for the perfected use of reason and common sense.
Patanjali, a saint who lived in s.III B.C was a erudite of the subject, even being the author of one of the most important texts of yoga. He defined yoga as the preparation of a profound transformation, following the ancient forms of behavior and thinking, producing the calm and guide to interrupt the ordinary mind activities.
If the goal of yoga is not attained, a perpetual poor and stable state is established in the individual. Unfortunately, people live in that way permanently.