Illuminance is a measure of how much light is received on a surface. It is quantified in units called lux, which indicate the amount of light per square meter. Higher illuminance means a brighter area, while lower illuminance indicates dimmer lighting. This measurement is important in various fields, including photography, architecture, and workplace safety. The concept of illuminance helps in designing spaces to ensure adequate lighting for activities. For example, offices require specific illuminance levels to promote productivity, while theaters may use lower levels to create a certain atmosphere. Understanding illuminance aids in achieving optimal lighting conditions.