A voucher is:

a file that includes the purchase order that was send to the vendor, the vendor invoice listing the cost and quantity of items purchased, and the internal receiving reports that verify the purchased items have been delivered.

a figure that includes the sale order that was send to the dealer, the vendor invoice listing the cost and quantity of items sold, and the internal receiving reports that verify the purchased items have been delivered.

a report that includes the purchase order that was send to the vendor, the vendor invoice listing the quality and quantity of items purchased, and the external receiving reports that verify the items have been sold.

a mammogram that includes the purchase order that was send to the purchaser, the purchaser invoice listing the benefits and quantity of items purchased, and the internal receiving reports that verify the purchased items have been sold.