Frankly Speaking: The New Age of Book Printing
The book printing market is now a hodgepodge of terminology for digital and offset printing, short-, medium- and long-runs, print-on-demand and long-tail applications. Publishers, printers and the ecosystem that supports them seem to define many of the most important concepts of new book printing technology differently.
Offset vs. Digital
Offset litho prints from a static image carrier (plate), and every impression is the same. If an impression is different, you did something wrong. Because of the nonproductive period of press setup called "makeready," short-runs are not economically justified for offset litho. But, because makeready is absorbed into each printed unit, unit costs decline as run lengths increase. A newer offset system may reduce makeready, but it will always exist.
Digital printing includes only those toner and inkjet technologies that regenerate the image for each impression. Thus, every impression can be different. All printing today uses digital technology, but digital printing specifically refers to the impression regeneration. The advantages are electronic collation (printing a book's pages in order), versioning (different book versions), personalization and one-off printing. Digital printing unit costs remain constant over all run lengths.
A major difference between the two is that digital printing has no makeready. Theoretically, with digital printing, you can have your book(s) almost immediately, or on-demand. Some use the term on-demand as a euphemism for "fast." The decision to print digitally or by offset usually is based on run lengths—shorter runs go digital, and all other runs go offset.
On-demand vs. Short-run
On-demand means the book is printed when an order is received, and no physical inventory generally exists. On-demand often is called print-on-demand (POD).
Short-run generally means less than 1,000 books, which may be printed digitally or by offset. Digital printing loses some cost advantage as run length increases, although newer, roll-fed inkjet printing systems are pushing digital run lengths higher.