Reflective Type
This method uses ambient light to display. Such type of display depends on the reflection of the ambient light. Display can not be conducted in dark due to its dependence on the ambient light in this type.
Transmissive Type
Independent of ambient light source. Backlight needed.
Both ambient light and backlighting can be used. Backlighting is not necessary when ambient light is strong enough. Backlighting is needed when ambient light is too weak.