LCD on means the entire backlight layer is turned on, so LCD is either fully on or fully off, while OLED each pixel is independent, so OLED can light some pixels individually
LCD screen display https://stm32micro.com/real-ti....me-monitoring-flow-i
LCD screen module https://tmsmcu.com/what-are-th....e-advantages-of-lcd-
TFT LCD screen https://tmsmicro.com/detailed-....analysis-of-the-type

image