.epub ebook files work great with ereaders and reading apps like Kindle, Kobo, and Apple Books on desktops and mobile devices. Note: Amazon replaced their proprietary .mobi file format with .epub in 2022. Use this guide to load files to your Kindle ereader or app.
.pdf is a standard file type that works on pretty much all devices including computers and within mobile apps, but it's just not as pretty... :/
