Switches are electromechanical devices. The are used to control the path of current or energy flow. Power switches are used to turn on and off loads. The contacts should be robust and have immunity to sparking and corrosion. Switches for signals need to be gold plated for low contact resistance and within a sealed enclosure. Toggle Switches with metal levers are used in signal switching and range selection. Some may be switching Low DC or AC Levels less than 5V and currents in uA.