Sorry! Didn't mean to confuse you.
DRM is digital rights management - used to limit usage of digital content. It's on some ebooks that you buy eg from the sony store, and it's intended to stop you passing a book you buy on to someone else. I bought epub books from Waterstones in the UK, and these have DRM so I needed Digital Editions to access them. I haven't needed Digital editions for anything else.
Hope that all made sense, but if there's anything else that's not clear then just say. It doesn't take long before you start using all this jargon like you've been speaking it all your life
