Good day, sb-alehzayis,

You have the option to apply the discount to a specific line or to all items on the invoice. You may choose between these two options as they have different calculations.

I've added screenshots below to see the difference.

Check out the Sales and customers page to learn all your company's income and customers. It includes subtopics to help you manage and handle your revenue.

Should you need anything else, please let me know. I'm always around here in the Intuit Community to help you out.