The official business definition of a Purchase Order (PO) is a document that is issued by a buyer to a seller, indicating the type, quantity, and agreed price for goods or services the seller will provide to the buyer. It is a legally binding document that serves as an agreement between the buyer and seller, and is often used to control the purchasing of products and services from external vendors. The PO is typically generated by the buyer, who sends it to the seller with instructions for the goods or services they wish to purchase. The seller then confirms the order and sends an invoice to the buyer for payment. The PO is a key document in the purchasing process, as it serves as a record of the agreement between the buyer and seller, and is used to track and manage the purchase. It also serves as a reference for both parties when disputes arise.