The Lutron 1K Dimmer uses patented triac technology for dimming lights. This component actually turns light on and off 120 times per second to create the dimming effect. The longer the light is ON versus OFF the brighter the output. Conversely, the longer the light is OFF versus ON the lower the output.
The unit is turned on, or off by rotating the switch. Dimming function range goes from zero to 100%.
NOTE: This single-pole dimmer is for use with incandescent lights only.