1. Monochrome refers to the luminescent material with only one color on the display screen, mostly single red.

　　2. The two-color screen is generally composed of red and green LED diodes.

　　3. Three-color (full-color) screen, composed of red, green (wavelength 570nm), and blue; and true color, composed of red, pure green (wavelength 525nm), and blue.

Secondly, it is divided by environment: indoor, outdoor and semi-outdoor LED display.

　　 1. The semi-open air curtain is between indoor and outdoor, with high brightness, and can be used outdoors in the sun. The screen is sealed, usually on the roof or window.

2. The indoor screen area is generally very small (a dozen square meters), and the dot density is high. The viewing distance is a few meters away under direct sunlight or ambient lighting. Because it is indoors, it does not need to be open-air. Sealed and waterproof function. Indoor display screen dot matrix modules are the main ones, because the display brightness requirements for indoor use are not high.

3. Outdoor display screens have a small area of tens of square meters, large ones of hundreds of square meters or even thousands of square meters. The dot density is relatively sparse (mostly 1000-4000 dots per square meter), and the luminous brightness is 3000-6000cd/square meter (toward Different, the brightness requirements are different), in direct sunlight conditions, the viewing distance is tens of meters, because it is outdoor, it is necessary to use a waterproof box, and the screen has a good resistance to wind, rain and lightning.