MOBI is an ebook format used primarily by Amazon Kindle devices. It’s based on the open standard for digital publishing and allows for content reflow and support for images, links, and embedded fonts. MOBI files are widely used for ebook distribution and are compatible with various reading apps.
AZW3 is a proprietary ebook format developed by Amazon for Kindle devices. It supports more complex content than older formats like AZW, including HTML5 and CSS3 elements, embedded fonts, and multimedia. AZW3 files provide better compatibility and richer features for modern Kindle devices and apps.