You wake up in the morning and decide to go read a book, or your reading class suggests you read a certain book. You rush to Google to get a copy but you find there are no free PDF versions and the only closest you get is an EPUB. You download the file but your PDF reader fails to open it and you rush back to Google and type “How to open an EPUB file”. The answer is simple, what you need to open an EPUB file is an EPUB Reader.
EPUB is a short form for electronic publication and it is an extension used by many to store their eBooks. I have found EPUBs very useful because most of the good books are not available in PDF for free. You have to part with some dollars to own them. Most of these books appear for free as EPUBS.
Examples of EPUB readers you can use are Lithium, Moon+Reader, ReadEra, Aldiko, FullReader. Those are the most common for android however you can find some on the iOS store. On Windows, you can use Iceream, Calibre, Cover and more. Alternatively you can get EPUB extensions like EPUB reader on Firefox and MagicScroll on Chrome.
Personally, I use Lithium on Android and it has been very helpful in my quest for knowledge.
