Is there a real big difference between a dmd and dds?

None: I am not a dentist but as far as i know, the dmd and dds degrees are equivalent. Both are dentists. I believe it is similar to the fact that there are two degrees for doctors, M.D. And D.O.

Not any more: Historically, most dental schools offered the dds degree. A few, such as penn and tufts, restructured their curriculum to provide a greater understanding of the connection between the health of the mouth and the rest of the body and chose to use a different designation. Today, however, there really is no difference in the quality or scope of education leading to either degree. Both are well trained.