Screen brightness refers to the level at which an electronic display, such as a computer monitor or smartphone screen, emits light. It is measured in terms of candela per square meter (cd/m²) and can be adjusted by users to suit their preferences or viewing conditions. A higher brightness setting will make the display appear brighter, while a lower setting will result in a dimmer image. Adjusting screen brightness can help reduce eye strain and prevent discomfort when using electronic devices for extended periods of time.