Calibre – eBook Management & Synchronization Software (Multi-OS) eReaders aren’t just portable displays to read your eBooks on the go.
The difference lies in the display technology. Where normal displays use liquid crystal-filled pixels, and beam the image on your retina with what is in fact a big flashlight, e-ink technology uses no additional light-source. In fact, they really use an ink-like set-up. The result? E-book management. Calibre Manages Your E-Book Collection - Ebooks.