Capacitive sensors are devices that detect changes in capacitance, which is the ability of a system to store an electric charge. They consist of two conductive plates separated by an insulating material. When an object, such as a finger, comes close to the sensor, it alters the electric field between the plates, allowing the sensor to detect the presence or absence of the object. These sensors are commonly used in touchscreens, such as those found in smartphones and tablets, as well as in various industrial applications. Capacitive sensors are favored for their sensitivity and ability to detect non-metallic objects, making them versatile in many settings.