TRANSFLECTIVE is a portmanteau of TRANSmissive and reFLECTIVE. A transflective LCD combines the best features of a reflective LCDs and transmissive LCDs.
A transflective LCD will reflect ambient light, allowing it to be visible in normal office light without using a backlight. In bright sunlight, a transflective LCD is still visible and does not wash out–this is also called “sunlight readable.”
A transflective LCD also allows light from a backlight to transmit through the LCD. So a transflective LCD with a backlight can be seen in dark environments.
In short, a transflective, backlit LCD can be used in all lighting environments, from complete darkness to full sunlight.