Yoga is the joining of the mind and consciousness. In the western tradition, everyone talks about their mind. In the Indian tradition, you have manus which is an instrument. In the western tradition, the word mind is frequently taken to stand both for consciousness and for the instrument where judgments are made. While in the Indian tradition there is a distinction, the mind has an ego or ahamkara and chitta which is a memory bank, and buddhi which is judgment.
Listen to Prof Subhash Kak, Regents Professor of Electrical & Computer Engineering, Oklahoma State University talk about Indian Science, Yoga, and Art.