The Graphics Device Interface (GDI) provides Windows programs with a unified system for presenting graphics to the user. The GDI is used for video (display) and the printer systems.

For printing, the GDI accepts application print requests and translates them into Device Driver Interface (DDI) calls specific to the graphic capabilities of the end printing device.

When an application sends a print request, the GDI and the DDI produce a file called the Print Job.

There are two different types of print jobs:

  1. Raw Print Job
    Raw Print Jobs contain the sequence of instructions for the printer that will produce the job.

  2. Journal File Print Job
    The Journal File Print Job contains a list of the Device Driver Interface calls that will produce a raw print job.