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 concept is important in various fields, including photography, architecture, and workplace design, to ensure adequate lighting for tasks and comfort. The level of illuminance can be affected by several factors, such as the type of light source, distance from the source, and any obstructions in the environment. Proper illuminance is essential for activities like reading, working, and driving, as it impacts visibility and safety.