The order product page

Use the order product page to edit the record on the [Products] detail in the [Orders] and [Invoices] sections.

Order/Invoice	The record number, for which the product is added. This is a non-editable field.
Product name	The name of the product that was added to the record.
Unit of measure	Measuring unit for product quantity. When you select a product from the lookup, the field is filled in with base unit specified in the [Base price] block of the product page. You can select another unit for this field, if it was added on the [Units] detail of the product page earlier.
Quantity	Number of product units in the order.
Price list	Price list that specifies product price. Base price list is selected by default. Use the “Base price list” system setting to specify the base price list.
Price	Price of the product. This is a non-editable field. When you select a product from the lookup, the field is filled in with base price from the base price list that is specified on the product page. The price is converted to be displayed in currency of the order. If you change the value in the [Price list] field, the product price will be updated automatically.
Amount	The total cost of the selected quantity of products. The field is non-editable. Its value is calculated automatically based on the price per one unit and the quantity of products.
Discount, %	The percentage and amount of discount given on the product. The values in these fields are interrelated, therefore, when you change the value in one of the fields, the value in the other field will be automatically recalculated. If you change the price and/or quantity of the product, the value in the [Discount amount] field will be automatically recalculated as well.
Discount amount
Tax	Tax type. For example, “VAT“. By default, this field is filled in with the tax value from the product page.
Taxes, %	The percentage of the selected tax. The information in this field is non-editable and is filled in based on the [Taxes] lookup.
Tax amount	This is a non-editable field. The value is calculated based on the percentage of tax and total cost of the product.
Total	The total cost of products including any applied discount. By default, it is assumed that product price includes taxes. If necessary, you can disable this option by changing the “Price includes taxes” system setting. In this case, tax will be on top of the product price.

The cost of product in the order depends on the order currency and the currency in which base price of the product is specified in the [Products] section. Thus, if the currency of a product's initial price is the same as the order currency, the order product price will be equal to base price of the product. If the currencies are different, the product base price will be converted to order currency using the exchange rate specified in the order. The conversion is first done from the currency of the product's base price to base currency, and then - from base currency to the order currency.