What's the difference between the EPUB and PDF format?

EPUB is an open format standardized by the World Wide Web Consortium (W3C) based on the XML language. It is designed to simplify on-screen reading. Its main advantage is dynamic reformatting, where the layout of text and images adjusts automatically when the font size is changed. This format ensures comfortable reading on any device, whether on a computer, a reader, a tablet or a smartphone.

Created by Adobe, the PDF format is now an open format standardized by the International Organization for Standardization (ISO). This format guarantees uniform layouts (fonts, images, etc.) regardless of the medium on which the file is read. PDFs offer comfortable reading on a computer and most tablets but makes reading on an e-reader or smartphone more difficult, if not impossible.