The most common type of spooling is print spooling, where print jobs are sent to a print spool before being transmitted to the printer. For example, when you print a document from within an application, the document data is spooled to a temporary storage area while the printer warms up. As soon as the printer is ready to print the document, the data is sent from the spool to the printer and the document is printed.
Print spooling gets its name from technology used in the 1960s, when print jobs were stored on large reels of magnetic tape. The data from these reels was physically spooled to electrostatic printers, which printed the output saved to the tape.