To understand why the **rear license plate light** is used simultaneously with the high beam and dipped beam lights, it is important to know the purpose and use of each type of light on a vehicle.

- **High beam light**: This light is used to illuminate long distances on roads outside towns or cities, especially at night or in poorly lit tunnels. It is a powerful light that can dazzle other drivers, so it should be used with caution.

- **Dipped beam light**: It is mainly used at night on all types of roads and during the day in specific situations such as tunnels or temporary lanes. It is also used when there is a risk of dazzling other drivers with the high beam lights.

Both high beam and dipped beam lights are essential for the visibility and safety of the vehicle in different driving conditions. The **rear license plate light** is a light that must always be on when the vehicle is in use, as it allows the license plate to be visible to other drivers and authorities, thus ensuring the identification of the vehicle at all times.

Therefore, it is logical that the rear license plate light is used simultaneously with the high beam and dipped beam lights, as these lights are turned on in situations where visibility is crucial, and the identification of the vehicle must remain clear.