What is HID lights?

High intensity discharge (HID) lights are known for their high luminous efficacy, meaning their ability to produce lots of light at proportionally low amounts of wattage. HIDs function by sending electrical current through a filament and exciting the gas inside the glass envelope, thus producing an electrical arc. HIDs are typically filled with a noble gas (argon, krypton, xenon, and neon) and another gas, most often sodium, metal halides, or Mercury.