The LED is a PN junction diode which emits visible light when the forward bias applies across it. Whereas the LCD uses liquid filaments which are filled between glass electrodes for the emission of light. The LED stands for Light Emitting Diode whereas the LCD stands for Liquid Crystal Display

When the lamp's switch is in the off position, the LED bulb still emits a very dim light, whereas the halogen ones do not. What is happenning here? Is this normal? From my limited knowledge I would guess the lamp's circuit has some residual current which is not enough to light up the halogen bulbs, but makes the LED emit the dim light observed. led