QH technology consists of a globe connected to power. They work by running 12 or 24 volt power through a tungsten filament that is surrounded by inert gas (gas that will not burn or ignite) inside a quartz glass bulb. Quite simply, power is applied to the filament, it is heated until it glows and produces light. The inert gas sealed inside the quartz glass prevents the filament from burning and destroying itself.

HID technology consists of a globe, starter and ballast connected to power. The globe is a quartz tube filled with Xenon gas, with tungsten electrodes housed at each end. The bulb functions by running 23,000 volts through the tube (generated by the starter) that ignites the gas and produces an arc of light between the electrodes. Once ignited, the ballast regulates the voltage back to 85 volts to keep the arc running.

Standard headlights use 55 watt QH globes and have an average lifespan of 200 hours of operation. HID globes in comparison generate around 3 times the light output of a 55 watt QH, however use a third less power (35 watts), and have a lifespan of about 2000 hours – about 10 times that of QH.
Note: Xray Vision QH Driving Lights use 100 watt QH globes, providing superior performance over standard vehicle headlights.

QH and HID also run different Correlated Colour Temperatures: QH is around 3500K (yellowish is appearance), whereas HID run at 6000K (icy white, close to daylight).

In short, HID globes are brighter, last longer, use less power and produce light that is close to daylight in colour, compared to QH globes.