Printer Driver

On UNIX systems, printer drivers are typically implemented as filters.On MS-DOS, there have been no system-wide printer drivers; every application was shipped with its own printer drivers, which were fundamentally descriptions of printer commands. Printers, too, have been supplied with drivers for the most accepted applications. In additions, applications incorporated tools for editing printer description, in case there was no ready driver.

On Microsoft Windows and Macintosh systems, printer drivers create a part of GDI. Programs then use the similar standard APIs to draw text and pictures both on screen and on paper. Printers which use GDI natively are commonly referred to as Winprinters and considered problematic for other operating systems.Win32 APIs also permit applications to send data directly to spooler, bypassing the printer driver; however, few applications actually use this option.Printer drivers should not be confused with print spoolers, that queue print jobs and send them to printer one after the other.

On UNIX systems, printer drivers are frequently named front end and printer spoolers back end of the printing system.Backends are also used to determinate the available devices. On startup each backend is asked for a list of devices it supports, and any information that is available

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