Offset printing, is a development of lithography, it is based on the principle that water and grease do not mix, so that a greasy ink can be deposited on grease-treated printing areas of the plate, while nonprinting areas, which hold water, reject the ink. The offset process is still the most efficient method of printing for large volume printing products.
Digital printing is a method of printing from a digital-based image directly to a variety of media. Digital printing has a higher cost per page than more traditional offset printing methods, It also allows for on-demand printing, short turnaround time.