The type of lamp is the largest factor in the characteristics of the light beam. The most important aspects are the colour of the light, and the light intensity.
Although today all headlamps are equipped with white light, there are important differences in the shade of white. The closer the colour of the light is to daylight, the higher the visual comfort, for example.
The glare of a light source is a function of how bright it appears in comparison to the surrounding light conditions. There are strict laws governing how bright the headlights of a car can be. This is to make sure other drivers are not dazzled, which could be a risk to your safety as well as theirs!
More intensity in light results in more glare. To avoid glare it is necessary to have your lights set properly. If you had a lot of weight in the rear of a car, it could cause glare for oncoming traffic; therefore all cars have some sort of levelling. This can be either manual or automatic.
Some weather conditions, such as fog or snow, reflect the light from your own headlights, causing glare. Auxiliary lights, like fog lamps, can help to combat this.