HID (High Intensity Discharge) commonly known as gas discharge offers many technological advantages over conventional halogen lights. Most notably, higher colour temperature, reduced heat and a considerably longer lifetime (on average 10 times that of a standard halogen bulb). The light is produced by two electrodes positioned close together in a small gas-filled quartz tube. The illumination of an HID light is considerably brighter and greater compared with a halogen light.
In other words twice the illumination of a 70W halogen for only half the power consumption. You will also get a light similar to daylight.