Why is lighting design an important aspect for filmmakers?

The meaning of lighting goes beyond brightness and darkness.

All the filmmakers know how important it is to get it right. Lighting is a very important detail to record a successful film, as the cameras respond in a different way our eyes do. It has many reactions when  reflected or transmitted.

The lights guide the mood and shows the genre of the film. We can mention horror movies, they always use shadows to set the atmosphere and the feeling of the film.

"prior to 1910, these new artists were called neo-impressionists, and they believed that "modern paris" was the proper subject for their paintings."

this is the text provided by the program, disregard other answers, as they are confusing and based on loose knowledge of the subject.   : )