A PPD (PostScript Printer Description) file customizes the behavior of the driver for your specific PostScript printer. It contains information about the output device, including printer-resident fonts, available media sizes and orientation, optimized screen frequencies, screen angles, resolution, and color output capabilities. It’s important to select the correct PPD before you print. Selecting the PPD that corresponds to your PostScript printer or imagesetter populates the Print dialog box with the available settings for the output device. You can switch to a different one to suit your needs.
Applications use the information in the PPD file to determine which PostScript information to send to the printer when printing a document. For example, the application assumes that the fonts listed in your PPD file reside in the printer, so they are not downloaded when you print, unless you explicitly include them.
For best printing results, Adobe recommends that you obtain the latest version of the PPD file for your output device from the manufacturer. Many print service providers and commercial printers have PPDs for the imagesetters they use. Be sure to store PPDs in the location specified by the operating system. For details, consult the documentation for your operating system.