Your original question was too general.
It seems that there are at least four basic flavors of printers. Some
printers function in more than one flavor.
GDI (or printers that only accept data in a graphics dot oriented format.
Postscript
Mfrs printer language specific, such as Epson's Esc P2
Ascii (Some dot matrix, teletype, formed character printers)
Others that defy easy categorization into the above
Page printers, character printers, line printers, etc. can belong to one or
more of the basic "flavors"
And, printers that have capabilities of some of the above, possibly via
emulation. Plotters can fall into this category as well.
Special purpose printers (devices) that are not really part of the above
categories, and may have some printer like capability, but really have a
main use other than a "printer" An example might be a device used to print
or cut out letters for signs. Another might be a device that drives a high
speed bit used to "mill" 3d objects, such as a desk top name plate or a
carving.
In the absence of applications that do "non standard" things, the object to
be printed usually exists as a GDI image. The application usually converts
the object to a GDI or vector image, or very occasionally these days, to
ascii.
The printer driver then converts the GDI compliant object data into
something usable by the printer.
To really get into this sort of thing, you will need to obtain various SDKs,
either by download from MSDN, or by subscription.
Usually, special purpose software related to printing either behaves as any
other application that has printing requirements, or in some way modifies
data during the printing process as the data moves between the various
printing modules (system and device specific) Since device mfrs seldom
release enough information to determine how a specific printer driver
behaves, you go into a trial and error mode, even with full windows
development documentation and software.
It's not uncommon to need to make windows think your software is a printer
driver module, and make the mfrs printer driver think your software is part
of windows, if you are doing something out of the normal flow of things.
"I can't provide any further details, these must be kept confidential."
