Print on demand (POD)
Sometimes called publish on demand, is a Printing technology and business process in which new copies of a book (or other document) are not printed until an order has been received. Many Academic publishing, including University presses, use POD services to maintain a large Backlist; some even use POD for all of their publications. Larger publishers may use POD for reprinting older titles that had been out of print or doing test marketing.