What makes Yoga different from, say, gymnastics?  That is not to say that a gymnast can't be doing Yoga, but there is a fundamental difference in the goals that a gymnast and a Yogi pursue, even though at times they may appear to be doing the same thing.

By infusing every cell of the body with pure awareness, the Yogi fulfills the primordial need of every being, every creature, every plant - to become conscious.  It is the need to become conscious that drives evolution and is the force of life (Prana).  By fulfilling this need, a Yogi achieves the ultimate bliss, because by making every cell of the body conscious (full of Prana), he or she ultimately finds the meaning of life - self-awareness and consciousness.

When someone achieves mastery over what they do, whatever that endeavor may be, they can't help but spiritualize the action -  the action or creation becomes more infused with Spirit.  That is why when an action crosses over into the realm of mastery, when it is now Art, it touches us in so many profound ways - because it operates at that level.  That is what sets the Master apart from the novice.

Once we are in the presence of a Master, their spiritualized action (actor being one with the action) sets in us the desire, the urge (tapas) to follow because we can sense their joy and want to experience it too.  That's why a true Guru is one who inspires us to become Masters, one who walked the bath and embodies the Spirit.

It is not enough, though, to infuse the body, creation or action with your Spirit. This happens often enough - the accidental Yoga, so to speak.  Each and every one of us can probably recall a moment of pure joy, when we were totally in the moment, one with our action.  However, that moment is fleeting and we are often not aware of it or appreciate it until it passes. 

A Yogi, however, sets an intention to find that moment, uses specific tools to hone awareness, and the goal for the Yogi is to become conscious of being conscious at the precise moment it is happening.  The Yoga Sutras say that the moment we become conscious of being conscious - nothing more needs to be done, the Yogi has achieved enlightenment.