Resistive touch screen
A resistive touchscreen panel is composed of several layers, the most important of which are two thin, metallic, electrically conductive layers separated by a narrow gap. When an object, such as a finger or a pen, presses down on a point on the screen's outer surface the two metallic layers become connected at that point: the panel then behaves as a pair of voltage dividers with connected outputs. This causes a change in the electrical current which is registered as a touch event and sent to the controller for processing. Resistive Touch Screens are durable and resistant to humidity and liquid spills. But they offer limited clarity, and the surface can be easily damaged by sharp objects.