Well, in a short manner I'd say the art of Yoga is achieving the correct exercise of it.

The science of Yoga is already published in hundreds of research publications, by medicine in particular, proving the benefits for the whole motion of the body, heart/lung health, all the way to resilience against stressors.

If you want a unified approach, one should mention the spiritual attitude.

Dear, it is not good to say the science published in research publications are good enough and correct. But what about the science and art published in Classical text of Yoga?

I think both Art and science are same. Uli Plank