Switches come in a variety of shapes, sizes and methods of operation. Toggle switches were the earliest developments in domestic power circuits. The development of electronics and its application in industry has necessitated in different forms of switches with miniaturization. Starting from the manually operated on/off switch, a variety of switches are available, with some operating automatically according to the function for which they are installed.
Among the different types of switches used in circuits, there are pressure and vacuum activated switches including ones activated electrically as well. The most significant recent development is the touch switch extensively used in hand held electronic appliances. Significantly, a touch switch does not have any moving parts.