A purchase order is an official document that serves as a contract between a supplier and buyer. It outlines the details of an intended purchase, such as the quantity and price of goods or services that are to be bought. By issuing a purchase order, the buyer agrees to pay for the items or services specified in it.

On the other hand, a purchase requisition is an internal request from a buyer to his/her purchasing department, asking them to acquire certain supplies or services. It’s a communication tool that initiates the purchasing process. The purchase requisition form outlines the type and amount of materials needed, and is used to obtain budget approval before any purchasing decisions are made.