The visual environment dominated by lighting has a more direct impact on most people than the thermal or auditory sensations of the environment.
The first purpose of lighting is to create appropriate visibility without causing excessive glare. The light source can be electric light or natural light. However, natural light is only used for a short time and mainly through windows on the side walls, so its use is limited.
Electric lighting can provide more controllable light distribution and more flexible use of space. The design of electric lighting is not limited to the first purpose mentioned above, but covers a wider range.