Have you ever done yoga?
I have just started to learn yoga.  Very much a beginner.  Do you know it well?
I know its history more than its practice. There is a broad variety of schools, practices and goals in yoga.
What are some of those?
The most well known types are Hatha and Raja yoga
Are those both taught in the states?
Yes. Yoga as a whole became popular in the 80s in the Western world.
That's a while ago.  What are the differences between the Hatha and Raja?
Hatha focuses on the body, and is more physical. Raja refers more to the goal of yoga and not a method of attaining it.