Screen brightness refers to the intensity of light emitted from a display, such as a computer monitor, smartphone, or television. It is measured in nits, with higher values indicating a brighter screen. Adjusting screen brightness can enhance visibility in different lighting conditions, making it easier to see content in bright sunlight or dim environments. Most devices allow users to manually adjust screen brightness through settings or buttons. Automatic brightness adjustment features are also common, using sensors to detect ambient light and adjust the screen's brightness accordingly. This helps improve battery life and reduces eye strain during prolonged use.