Select this option to add a flat amount as a discount to the entire invoice (quote, credit note, cash sale, order).
Fixed percentage discount to the whole
Select this option to add a percentage-based discount to the entire invoice (quote, credit note, cash sale, order). Currently this type of discount must be added after all other items in order to calculate the amount correctly.
Apply line-by-line discounts to specific items
Select this option to enable the discount column for each item on the invoice (quote, credit note, cash sale, order). Line item discounts must be entered as a percentage.