Much of the business transacted on the Web today takes place through information exchanges made possible by using documents as interfaces. For example, what seems to be a simple purchase from an online bookstore actually involves at least three different business collaborations—between the customer and the online catalog to select a book; between the bookstore and a credit card authorization service to verify and charge the customer's account; and between the bookstore and the delivery service with instructions for picking up and delivering the book to the customer.
