Why do certain lights operate on 110V or 220V versus 12V or 24V ? And why does voltage even matter? It’s all about wattage, right? Not exactly. Lights operate on different voltages, and in America, 110V, 12V, and 24V lighting systems are the most common, while in Europe, 220V, 12V and 24V. So what are the differences between them? 110 volts and 220 volts are the standard voltage supply for American and European homes. This is the voltage that travels to your home from your local utility substation. 110 or 220 volts is commonly referred to as “line voltage” by electricians. Nearly all indoor residential light fixtures and appliances in the U.S. run on line voltage. A 120-volt light bulb can typically be screwed into an indoor light fixture and operate correctly without further complication. Likewise, most appliances run on 120 volts and can simply be plugged into an indoor outlet. Meanwhile, 12 volts and 24 volts are commonly used for outdoor lighting and are referred t...