The pdf version is basically paper in an electronic format. The pages are static, fixed and unchangeable. You can’t customize a PDF file but it is easy to use. However, when you open a PDF document on a small screen device, you will have to zoom, pan and pinch to read the document. PDF files can be read on almost all devices but you cannot read them on all eReaders. They are designed for big screens like a desktop computer or a laptop.
An ePUB has become the standard format for digital publications. It’s the most preferred type of file format for eBooks. An ePUB file has the ability to reflow its content. The ePUB document fits smoothly around the screen you are looking at. The page breaks depend on the size of your screen. Th content on the page rearranges and realigns itself so you can have a good reading experience. The text arranges itself automatically according to the screen size of your reading device. EPUBs are compatible with a computer, smartphone, tablet and any eReader except Kindle.