 Such transactions often involve an extension of credit, meaning that a vendor would send a shipment of goods to a company before the goods have been paid for.Although real goods are changing hands, until an actual invoice is issued, real money is not.Rather, debits and credits are being logged in an accounting system to keep track of inventories shipped and payments 

When a price is included on a debit note,it is the price which the customer was actually charged for those goods.