A Purchase Order is a formal document used by businesses to record and manage the purchase of goods and services. It outlines the type and quantity of goods being purchased, as well as the payment schedule and delivery date. Once a Purchase Order has been sent out to a vendor, they must sign it in order to officially accept the agreement – meaning the buyer is legally obligated to pay for the items ordered.

On the other hand, a Requisition is an internal document typically used when ordering goods or services within a business. Unlike Purchase Orders, Requisitions do not include pricing information and are usually initiated by a department or individual within the organization rather than an outside vendor. They also don’t need to be signed, as no legal obligations are created by them.