What is POLED and AMOLED ?

There are several OLED types, the most well-known are POLED and AMOLED.

POLED is short for Plastic Light Emitting Diode, which is a display technology that uses a flexible plastic substrate instead of glass for the organic electroluminescent semiconductor to be deposited. As such, the POLED display panel can be bent, folded, or rolled up without breakage. 

AMOLED stands for Active Matrix Organic Light Emitting Diode, having a thin film transistor or TFT capable of controlling every flow of each pixel.  The AMOLED display has faster refresh rates than OLEDs and so provides a tremendous artificial contrast ratio in which each pixel transmits light resulting in better production. You can find this type of display on several new generations of iPhone models such as the iPhone X/XS, iPhone 11 Pro, iPhone 12, etc.