There are 3 main types of displays on the market – LCD, OLED and AMOLED.
LCD or Liquid Crystal Display is cheaper and also lower quality compared to OLED and AMOLED. LCD is built out of more component layers what makes him thicker against newer displays. Manly, LCD is made up of special liquid crystals that get illuminated by a fluorescent backlight. The quality of the image is lower, they show a lack of contrast (black color appears as gray), consumption of power is consistent and it’s not affected by the color on the screen. Compared to other displays, its better under direct sunlight.
OLED or Organic Light Emitting Diode. Its built out of fewer component layers then the LCD, what makes it thinner. OLEDs thin-film display is built out of organic material. When current passes through it emits light. On OLED you get much better black color. It consumes less power when displaying darker colors.
AMOLED or Active Matrix Organic Light Emitting Diode is a step up from the OLED display technology. Its driven by a special TFT technology. TFT plane activates on receiving electrical currents while TFT arrays are acting as switches for each pixel. Advantage against LCD is they are thinner and more flexible. AMOLEDs have faster refresh rate, no restriction on size display, higher contrast ratio and consume less power when darker colors are displayed. AMOLED display shows poor image under direct sunlight. When brighter colors are displayed, it consumes more power. Organic material has a shorter lifetime. AMOLEDs have even fewer component layers, what makes them thinner than OLED.
Putting it all together, LCD technology has been around for a while, while AMOLED is a newer one on the market and it uses newer technology. AMOLED is a better version of OLED. AMOLEDs and OLEDs are better against LCDs since they bring a better image quality, have faster refresh rates, higher contrast and resolution, more brightness, better viewing angles and are lighter and more flexible.