Kindle supports both AZW3 and MOBI eBook formats. They might seem the same, but there are some significant differences between them. For starters, MOBI tends to be quite basic and doesn’t allow authors to change the font or layout of the text. On the other hand, AZW3 is a more sophisticated format that supports many styles, fonts, and even multimedia content. Another significant difference is that AZW3 eBooks are automatically protected by Digital Rights Management (DRM). That’s one of the main reasons why this format is gradually replacing MOBI on Amazon.