Well assuming this is a serious question....
The H4 lamps in a C-14 headlight have two filaments, one used for high beam and one used for low beam. Both headlights are used for both high and low beam.
The low beam has a shield under the filament so that the only light that can come out of the bulb goes up and is reflected down. The low beam produces a light beam that only shines down below the light and forward, hence the term 'low beam'. This prevents blinding other drivers in oncoming traffic.
The front of the lamp is painted black so there is no forward light coming out of the bulb no matter which filament is used.
When you switch to high beams, the low beam filament goes out and the high beam filament illuminates. There is no shield around that filament (high beam) so the light is scattered all around the reflector and then forward but there is no cut off line and the light shines both above as well as below the headlight itself.
It is possible for either or both filaments to fail in either or both lights; more than one filament will not usually fail at the same time but sometimes a rider is not aware that one filament has failed and so it is not noticed until the 'other' filament fails also and the motorcycle has no high or low beams, depending on which filaments have failed.
There is a slight overlap on the low / high beam switch when both filaments are on at the same time; if you find that spot and hold the switch there (or use the Flash To Pass switch) you will notice that there is a lot of light being produced- that is because both sets of filaments are on at the same time and the lights are using at least double the power they normally would. They also produce a lot of heat so it is not really desirable to ride with the lights used in that way.
Brian
So what makes them "high" and "low" beams is just a matter of position?