HID and Xenon bulbs are the same thing, they just seem to be called HID's for the cheap aftermarket kits and Xenons for the standard fit headlamp units.

The reason the HID kits usually blind everyone is people put them in housings designed to be used with a normal halogen bulb. The HID (high intensity discharge) kit has a much higher intensity than a normal filament bulb, so the reflector just scatters the light everywhere instead of projecting a normal beam pattern at the road.

A Xenon headlamp unit has either a reflector or a glass lens that is designed to be used with a HID bulb, so it won't scatter the light everywhere, thus giving a good beam pattern.