simple on-off switch; one-way switch (UK); two-way switch (US)
Electrical switch with only two terminals, used for basic on/off control from a single location. Compare with 3路スイッチ (three-way) and 4路スイッチ (four-way) for multi-location switching.
See also: 三路スイッチ (さんろスイッチ) · ４路スイッチ (よんろスイッチ)
This light is operated by a simple on-off switch.
A one-way switch is the type that can turn the light on or off from only one location.