Resistive
Resistive touch screen with plastic pen
Resistive touch screens respond to the touch of almost any object.

To test if a screen is resistive use the plastic end of a pen.
If the screen is activated, it is resistive.

Capacitive
Capacitive touch screen with plastic pen Capacitive touch screen with finger Capacitive touch screen with c-stylus
Capacitive touch screens only respond to the touch of a finger or special styluses.

The iPhone and iPad are examples of capacitive touch screens.