eBooks are rather like websites
Designed to appear in the same way across platforms, eBooks are a package composed of html files, typically one file per chapter, with formatting specified by a style sheet. Standard re-flowable eBook are readable on a wide range of devices, from smart phones up to large desktop computers. The pages will adjust to fit the screen, with the text and images reflowing from page to page. Re-flowable eBooks will display in single columns, though pages on some devices can display side by side resembling a printed book.
Re-Flowable or Fixed Layout?
In cases where there is a need to maintain the exact layout of the printed book, there is an option known as a fixed layout eBook, where the exact look of the printed book can be maintained within the eBook. Page breaks are fixed and text can appear over background images. The drawback is that the text cannot be re-sized, and so the readability is greatly reduced on smaller screens. For this reason, fixed layout is recommended for children’s books and titles consisting mainly of images. The problem is obviated on devices such as iPads and Kobos, with the enlargement by pinch and zoom but this is not available as standard on Amazon Kindle devices
Continue reading: Formats and Devices.