Print on demand refers to a printing method where books, documents, or other materials are produced in small quantities as they are ordered, rather than being mass-produced in advance. This allows for a more efficient and cost-effective process, as materials are only printed when there is a demand for them. This method also allows for greater flexibility and customization, as each item can be tailored to the specific needs of the customer. Print on demand has become increasingly popular in the digital age, as it allows for quick and easy access to a wide range of materials without the need for large print runs or storage space.