Usage style refers to the province in which a vehicle circulates.
If a vehicle normally circulates in low risk provinces, then at the end of the month you are entitled to a discount in the mileage adjustment. No discount for high risk provinces.
Driving style means harsh braking and acceleration, as defined in the Information Set.
If you usually brake/accelerate sharply only a few times, then at the end of the month you are entitled to a discount in the mileage adjustment.
You can check your usage and driving style day by day from the section MyCar | Kilometres of the BeRebel app. Discounts are explained in detail in the Statement of Account at the end of the month.