A printer driver
is software used by computer programs to communicate
with printers and plotters. Printer drivers translate
the information you send from the computer into commands
that the printer understands. Usually, printer drivers
are not compatible across platforms, so various drivers
must be installed on the print server to support different
hardware and operating systems. For example, if you
are running Windows XP and you share a printer
with users running Windows 3.1, you might need
to install multiple printer drivers.
In general, printer
drivers are made up of three types of files:
Configuration or printer
interface file
Displays
the Properties and
Preferences dialog boxes when you configure
a printer. This file has a .dll extension.
Data file
Provides
information about the capabilities of a specific
printer, including its resolution capability,
whether it can print on both sides of the page,
and what size paper it can accept. This file
could have a .dll, .pcd, .gpd, or .ppd extension.
Printer graphics driver
file
Translates
device driver interface (DDI) commands into
commands that a printer can understand. Each
driver translates a different printer language.
For example, the file Pscript.dll translates
the PostScript printer language. This file has
a .dll extension.
These
files, which are usually accompanied by a Help
file, work together to make printing possible.
For example, when you install a new printer,
the configuration file reads the data file and
displays the available printer options. When
you print, the graphics driver file queries
the configuration file about your selections
so that it can create the proper printer commands.