Book VS Novels

A book is a physical container though, sure you could argue that the digital file is a book since it contains the text but in the same sense you could say that the e-reader, computer or the server hosting the file for web reading is also a book since you access the file through them.
It is not called an e-book because it is a book in the literal sense but because it is the closest equivalent to compare to and blurs the line.
Doesn't make it better or worse than a traditional bound book though.