They are the most common LED monitors that are produced today. Diodes are placed at the sides of the screen. Depending on a manufacturer and model, led diodes may be placed all around the screen, only on one side or only at the bottom of the screen. Because of this, the monitors are really thin.
Downsides with this design are the fact that some parts of the screen are brighter than the other parts. This known problem is called clouding or flashlight. Most often you may notice this when watching a dark scene in a darkened room.