This UML sequence diagram illustrates the process flow of a food ordering system. A customer places an order. It is forwarded to the restaurant through an order system. The restaurant checks the order's availability. It then confirms to the order system, which relays this to the customer. The customer proceeds to pay. A payment request is processed via the payment gateway. Once the payment is confirmed, the order system notifies the restaurant. This leads to order delivery. This diagram shows, clearly, the interactions in online food ordering systems. It illustrates the messaging involved.
