Google is your friend, but keep in mind that "yoga" is an umbrella term for a large variety of exercises. In particular, yoga as an Indian discipline aimed at reaching moksha, the liberation from the reincarnation cycle, is rather different from yoga as practiced in the West with the goal of losing 10 lbs.
I would add that the same thing goes for meditation, anaerobic exercise and aerobic exercise as well. All those terms include a lot of different activities.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.