The word “yog” comes from the sanskrit, the language of ancient India. It means to join, to bind, to connect, to attach, to unite. The Hindiword for addition, “jod”, takes it’s origin from the sanskrit word “yog”, like as the english word “yoke” also does.
All these word are related to each other and I think everyone can get his own idea, what yog is.
So Yog is not just the physical pratice, known as Asan(a). This is just a part of it. Traditional was this physical practice used as preparation for meditation.
Yog in the traditional way was meant as a path to realize your true self, to “awake”, what leads to lasting happieness. It is about to balance the body, soul and mind, experiencing the non-duality, being free from pain and perpared for the challenges of life.
Yog inclueds what you’re eating and drinking, what kind of work you’re doing, what kind of thoughts you have, when you’re waking up and going to bed, how your spend your freetime and even how you breath. I just remeber a very good friend of mine, who used to say, whatever she does is yog.