A spooler is a program control system for managing jobs for connected peripherals
. Simultaneous Peripheral Operations Online (SPOOL) is a type of background operation of peripherals, primarily printers, that runs concurrently with other computationally intensive programs. The spool program uses every pause in the application program to process the jobs that are normally queued
. A printer spooler manages the print jobs queued in the printer buffer and sends them to the printer. The order is based on the FIFO principle, First In First Out (FIFO).