The official business definition of the purpose of a purchase order is to provide a legal document between a buyer and a seller that outlines the details of a transaction. It serves as a binding agreement between the two parties, outlining the exact specifications of the goods or services being purchased, the price, delivery date, payment terms, and other important information. A purchase order also serves as a record of the transaction, and can be used to track the status of the order, payment, and delivery. In addition, it can be used to ensure that the buyer is getting the best possible deal and that the seller is providing the goods or services as agreed upon. By providing a clear and concise record of the transaction, a purchase order can help to protect both the buyer and the seller in the event of a dispute.