LED display works

The mainstream TVs and monitors that are being branded as "LED" are actually nothing other than LCDs that use LED backlighting instead of fluorescent. So they work just like LCD TVs/monitors/displays do, just that the LED backlights provide more precise wavelengths of light, allowing for somewhat better color reproduction and contrast. Back-lit models (as opposed to edge-lit models) can even decrease the brightness of some or all LEDs during dark scenes.

The LCD panel uses an active matrix of individual liquid crystals that change shape when electrical current is passed through them. The change in shape can allow light of certain colors to pass through, or it can block it.

https://dynamo-led-displays.co.uk