A Purchase Order (PO) is a formal document issued by a buyer to a seller, indicating the details of products or services being purchased. It outlines the type, quantity, and agreed-upon price of the goods or services. The PO serves as a contract between the buyer and the seller, providing legal protection for both parties. It typically includes the delivery schedule, payment terms, and any other special instructions. Once accepted, it confirms the transaction and authorizes the seller to deliver the items as per the agreed terms.