A customer applied a 10% off discount when placing an order.

When a customer applies a discount when placing an order, an order adjustment group summary is created. An order adjustment group summary is a record that represents a modification to the order amount,such as a discount, a surcharge, or a tax. An order adjustment group summary can have one or more order adjustments, which are the individual modifications that are applied to the order or the order items. An order can have one or more order adjustment group summaries, depending on how many types of modifications are applied to the order. References: Order Management Objects, [Order Adjustments]