Sheets refers to a single sheet of paper which consists of two sides.
If your file has 20 pages and it is printed single sided, 20 sheets will be used.
If your file has 20 pages and it is printed double sided, 10 sheets will be used.
Sheets refer to a single sheet of paper which consists of two sides. If your file has 20 pages and is printed single-sided, 20 are needed.
Updated over a week ago