If you have background printing enabled, you can continue to work on other documents while Word does this. As Word formats the pages, the computer saves them in a section of memory called the print spooler and then feeds them to the printer as fast as the printer can handle it. The printer begins to print as it receives data.
Modern printers have memory of their own, which speeds up the process a lot.
Long documents won t fit all at once into the printer s small memory. Your computer feeds the data to the printer in spurts. You may notice your computer is slow to react while it is feeding pages to the printer. Controlling Printing You will find that you often need to stop a print job before it finishes. Perhaps you had the wrong color paper in the printer.