A transmissive LCD depends on light from its backlight being transmitted through the LCD to your eyes. Transmissive LCDs are always combined with a backlight.
Transmissive LCDs can be seen easily in normal office lighting, and in darkness. Typically transmissive LCDs will not be visible in bright sunlight. It is possible to make a sunlight readable transmissive LCD by using a very bright backlight.
Transmissive LCDs are typically not used in systems where power consumption is critical since the display cannot be seen if the backlight is off. TFT LCDs as used in cell phones, tablets and TVs are transmissive and backlit.