Hiya, just wondering what the difference is, if any? When publishers speak about book design, do they just mean the cover? Cheers!
Book design includes both cover design and typesetting. It is a confusing term, and quite broad - basically it involves anything to do with the design, visual and layout of a book.
In short, book cover design consists of everything on the outside of the book, whilst typesetting involves everything between the covers (including in-text designs and illustrations).
Hope this helps!