Can somebody explain the difference?
Paperback is any book that is bound in paper wraps, while trade paperback usually refers to either a large, high quality paperback, or a medium-sized paperback.
Borrowing from another thread:
2) trade paperback
3) mass-market paperback
OK, thx we don't use these terms in Germany
Yeah, neither does Finland or Sweden. I think most of Europe doesn't use them.
In the thread I linked we did discuss about the usefulness of having so many different terms for paperbacks in the format field, but I don't see much happening at the moment...