The touchscreen is an input device and usually a layer above the electrically visible display of a data processing system. A user can provide input through simple or multi-touch gestures by touching the screen with a special stylus or one or more fingers or control the data processing method. Or can work using a pen. Users can use the touchscreen to respond to what is displayed, and the software allows them to control how it is displayed ; For example , zooming increases the size of a text.