The way it locates where your finger is on the screen is the change of local electrostatic field when your finger touches the glass of the capacitive surface. In this case, the human body (your fingers) is being used as an electrical charge conductor. It’s called capacitive because the technology is based on capacitive coupling that detects anything that is conductive or has a dielectric different from air. There are two common types of touch sensors/screens: capacitive and resistive. This has become the norm, especially when it comes to smartphones and tablets.
Touch sensors are increasingly used on displays.
