Books can be submitted as an EPUB file (.epub) or Multi-Touch (.ibooks). Textbooks must be created in iBooks Author and submitted as a .ibooks file.
DRM protects your book from illegal copying. It works differently depending on your book’s file type:
You can adjust your book's DRM settings in My Books in iTunes Connect. Learn more about DRM settings.
Yes, all copyrights and intellectual property rights will be retained by the original holders of the rights.