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.

Digital Rights Management (DRM) is a protective measure built into an ebook and designed to protect it from copyright infringement. It controls the various parameters of the digital loan, including its duration. Two DRMs are used in e-lending.

To read an ebook protected by ACS (the Adobe Content Server DRM), you must have an Adobe account, which you can sign-up for free, and a compatible e-reading application (see Reading Applications).

The LCP DRM (Licensed Content Protection) is an open solution developed by the Readium Foundation, which includes more than 80 members of the publishing industry. If you are using the new Aldiko application (beta)

 on your iOS or Android mobile device, this is the DRM that is used.

Tablets are multimedia devices that usually have most of the functions of a laptop computer. On the other hand, e-readers are dedicated reading devices. Their screen uses a display technique, called e-ink, that mimics the appearance of a printed page to lessen visual fatigue caused by reading on a screen. They are generally lighter than tablets and have longer autonomy (several days or even weeks).