Definition: In desktop publishing, a ream is 500 sheets of printing paper. Retail packages of common cut sizes of inkjet, laser, and copy paper are often sold by the ream.
A ream used to be about 480 sheets and where available today may be referred to as a short ream. To allow for waste, printers often purchased paper in reams of 516 sheets, known as a printer's ream. However, the 500 sheet ream is the standard unit in most places. A ream is the amount of paper used to determine the basis weight of paper.
More casually, a ream is used to mean a lot or a very large number as in "She goes through reams and reams of paper every week."
