Graphical Device Interface

The GDI calls the printer driver and provides information about the type of printer needed and the data type used. The printer driver responds by sending the GDI the fully qualified path name for the printer and printer escape sequences or Printer Job Language (PJL) which the GDI passes to the spooler.

Windows 3. x -based (16-bit) applications running on Windows 2000 use the Win16-on-Win32 (WOW) layer, which interacts with the applications through the GDI and with printer drivers through the device driver interface (DDI). The WOW layer translates 16-bit print and display APIs to 32-bit Microsoft® Win32® services. The GDI also provides services to the printer driver, including caching, client/server communications, and ANSI-to-Unicode conversion.