Touch Screen Technology - How It Works
There are three components used in touch screen technology:
The touch sensor is a panel with a touch responsive surface. Systems are built based on different types of sensors: resistive (most common), surface acoustic wave, and capacitive (most smartphones). However, in general, sensors have an electrical current running through them and touching the screen causes a voltage change. The voltage change signals the location of the touching.
The controller is the hardware that converts the voltage changes on the sensor into signals the computer or another device can receive.
Software tells the computer, smartphone, game device, etc, what's happening on the sensor and the information coming from the controller. Who's touching what where; and allows the computer or smartphone to react accordingly.
Of course, the technology works in combination with a computer, smartphone, or another type of device.