On-demand printing means printing done digitally.
The so-called large-scale printing equipment is unnecessary, and printing becomes possible only with digital data.
Since few copies such as dozens of copies can be printed, it is possible to cope with a small number of printed matter, not hundreds of prints such as hundreds of copies as in the past printing.

In the first place ondemand ondemand is English to respond to requests.
So, on-demand printing means printing according to your request.

In the words I hear earlier, there is on-demand broadcasting, but this means that you can also choose what you want to see.
Since it is said that it is requested, it means that you can print as many as you need according to the order.