A switch is a device used for operating electrical appliance.
In a switch on position the current passes through the appliance and it starts functioning.
In a switch off position the current will not pass through the appliance and it will not work.
A simplest switch consists of two contacts, one is fixed and the other is movable.
When the contacts brought together, the switch is closed (switch on) and current is flowing through the circuit.
In order to open the circuit, disconnect the contact (switch off).
Mainly switches are of two types:
2. Electronic switches