In touchscreen devices, the digitizer is a layer of glass that's designed to convert analog touch comments into digital signals. Both capacitive and resistive touchscreen devices have a digitizer. It's essentially a glass layer that's placed over the device's liquid-crystal display (LCD) layer.

Is a digitizer and screen the same thing?

So: Touchscreen (AKA digitizer) is the thin transparent layer of plastic, which reads the signal from the touch and transports it to the processing unit. It is the part that you can touch without disassembling the device. LCD screen is the panel that is inside the device, which displays the image.

Whats the difference between an LCD screen and a digitizer?

The digitizer is the only part of the display assembly that is responsible for sensing touch. Since the human touch is conductive it allows the screen to sense the location you touch. The LCD is only responsible for displaying the image on the screen.