Short description: This is a layer of control that imposes controls such as time limits and no copy/printing/sharing of Amazon (Kindle; .AZW), B&N (nook; EPUB), Apple (iBooks; EPUB), Sony (Reader; EPUB) e-books, OverDrive e-books (EPUB), and others. A common DRM tool/wrapper and/or format is Adobe Digital Editions (ADE).

DRM-free e-books can be opened by any device that reads the format the e-book is created in, and can be converted to be read in different formats and on different devices.

We'll focus on two formats: EPUB (which can be read by pretty much any digital device except the Amazon Kindle), and .mobi (the original version of Amazon's own proprietary .AZW format that can be read by Kindles). Amazon is switching to a new HTML 5-based format, .KF8, currently in use by the Kindle Fire.

The soda - e-book contents

The bottle - e-book format

The wrapper - DRM