This is the 14514th most frequent German word.
künstlicher
Artificial.
Here, 'künstlicher' modifies 'Beleuchtung' (lighting), specifying its nature as not natural but created by human means, i.e., artificial.
Der Garten ist mit künstlicher Beleuchtung erleuchtet.
The garden is illuminated with artificial lighting.
Here, 'künstlicher' relates to 'Intelligenz' (intelligence), a concept that is simulated by machines and not innate like in humans.
Künstlicher Intelligenz wird immer wichtiger für moderne Technologien.
Artificial intelligence is becoming more important for modern technologies.
In this sentence, 'künstlicher' describes the 'Blumenstrauß' (bouquet), indicating that it is man-made as opposed to natural.