What is the definition of LCD screen and OLED screen?

Regarding mobile phone screens, we often hear full screens, waterfall screens, etc. In fact, these are just the display form of the screen. In the final analysis, the common mobile phone screens on the market are mainly LCD screens and OLED screens.
LCD screens are commonly referred to as liquid crystal displays, which are relatively common and are generally found in homes. It does not have self-illumination characteristics and needs backlight support. These backlights can only emit white light. In order to project the three primary colors, a layer of color filter is needed to color.

The OLED screen is an organic self-luminous material, which itself has luminescent properties. When there is current passing through, these organic materials will emit light by themselves, projecting light in the three primary colors of red, green and blue. Especially when the black interface is displayed, the screen and the black panel of the phone are almost integrated. A more refined OLED screen is divided into AMOLED screen and Surper AMOLED screen.