Switch

Switch is an electronic component that is included in the input or set the current component due to the switch's function is to connect and disconnect the current flowing. On the switch there are two types of switch contacts is NO (Normally Open) and the switch is NC (Normally Close)

Switch NO (Normally Open) is normally not flowing currents 

Switch NC (Normally Close) is the normal state current is flowing 

The switch consists of several kinds of microswicth, ordinary switch, etc.