We all know what it means.

Except for me, apparently. I’ll have to update my vocabulary: backlight can mean front light.

E-ink displays are opaque. The Kindles with illumination use side-lighting with a layer of plastic that guides the light across the surface of the device. They are effectively front-lit using LEDs situated around the perimeter of the screen.

You can’t backlight e-paper. You could get a book light, though!