Question : how is a capacitive touch screen different from an AMOLED screen?
please could you also explain by giving the example of apple I-phone and samsung galaxy
capacitive touch screen

Best answer:

Answer by DG
Active-matrix OLED (Active-matrix organic light-emitting diode or AMOLED) is a display technology for use in mobile devices and televisions.AMOLED works by having a thin film transistor (TFT) layer consisting of an array of OLED pixels that form a matrix. Upon activation with electrical energy, the OLED pixels will illuminate light to render whites and colors; blacks will be shown to the eye due to unactivated OLED pixels.

Similarly LCD A liquid crystal display (LCD) is a thin, flat electronic visual display that uses the light modulating properties of liquid crystals (LCs).

While capacitive or resistive is the technology used to interact with the display.
Capacitive touch sreen is more responsive then resisitive touchscreen.Capacitive touchscreen responds faster with just a slight touch while resistive requires a hard press of finger.
Iphone uses a LCD display with capacitive touchscreen
Galaxy uses a AMOLED display with capacitive touchscreen
Nokia 5800 uses a LCD display with resistive touchscreen