this is a HID lamp
this is a BAllast or usually reffered as blaster with builtin Igniter.this particual type is more efficient and reliable then the one with an outside separate igniter.separate igniter increases the wiring hassle and burns out more frequently.The motor controller is separate ...
this is the HID light ...more bright but cooler in creating temparature due to usage of Xenon gas .... you touch the lamp and will burst...handle with extreme care and keep the moisture away
these are the color ranges (not the prices)
the lesser the better
thnks and i hope this is enuff info for you to go in market and buy the HID,s