GDI Printer Drivers
All Windows 2000 and later printer drivers consist of the following components:
A printer graphics DLL that assists GDI in rendering a print job, and sends the rendered data stream to the print spooler.
A printer interface DLL that provides both a user interface to the driver's configuration parameters, and an interface the spooler can call to notify the driver of print-related system events.
In addition, Microsoft-supplied printer drivers make use of printer data files.