Both, resistive and capacitive are coated with a thin conductive layer, usually Indium Tin Oxide (ITO). When you tap the screen, the two layers touch. A two-step process is used to measure the voltage in the X-direction and Y-direction, which allow the point of contact to be determined.
Compared to resistive touchscreens, which depend on electric contact by mechanical pressure, capacitive touchscreens use the natural conductivity of the human body. Depending on where the application will be used, and the exterior conditions will ultimately determine which touchscreen technology you should use.
Resistive touchscreens are widely used in manufacturing, medical environments, and ATMs, because they have a lower manufacturing cost, are more resistant to dirt and water and significantly reduce the risk of accidental touches (pressure needed to make the contact).