In price calculating process I often see something called adjustments.
Magento\Framework\Pricing\Adjustment\AdjustmentInterface
What are adjustments and how do they work?
It is classes which use
\Magento\Framework\Pricing\Adjustment\AdjustmentInterface
Adjustment uses for additional calculations for product price f.e taxes. You can implement own taxesl, using the interface, and make addititional calculations.