EPUB is an open format standard for electronic books.
An eBook format .epub is a digital version of a book that has been optimized for reading on screen.
It is designed to allow redistribution of the text according to the different capacities of electronic book readers.
This means that you can resize the text size, change the font and see an e-book on different screen sizes, the text is redistributed to fill the available display area.
Most e-book reader offer in addition a table of contents, bookmarks, notes and research into the content.
