A limit switch is an electromechanical device that is used to control machinery as part of a control system, as well as to control a mechanical process or to count objects passing a point. Limit switches are used to detect the presence or absence of objects, or to detect the limits of motion of an object, hence the name "limit switch". They are commonly found in industrial applications and can be used for a variety of purposes, such as to determine the position of machine parts, to provide safety interlocks, or to count objects as they pass by.