A touchscreen is an

input device

normally layered on the top of an

electronic visual display

of an

information processing system

. A user can give input or control the

information processing system

through simple or

multi-touch gestures

by touching the screen with a special

stylus

and/or one or more fingers.

[1]

Some touchscreens use ordinary or specially coated gloves to work while others use a special stylus/pen only. The user can use the touchscreen to react to what is displayed and to control how it is displayed; for example,

zooming

to increase the text size.