Discounts allow for the reduction of prices for selected variants, products, collections,
or categories by a given percentage or a fixed value.
There are two kinds of discounts in Saleor:
The promotion discount is automatically applied to all products included in the promotion,
without requiring any additional actions from the user.
In contrast, voucher requires the user to provide a code during the checkout process.
Both the promotion and voucher discounts can be used together.