Printing 2

It writes it to a printer file so that it can be printed at a later time. It will be formatted in a format that only the selected printer can read. It's basically in the same format the data is that goes to your printer after being processed but goes to a file instead.
I've never really seen a whole lot of use for this. I guess you could set your system up to have Printer type XYZ while there is no printer physically attached. You can then print it to a file, copy it to a floppy, and carry it to a machine that has that file.
To print it under DOS, you could copy the file to the printer I think. I have never actually done this though. Like I said, I don't see a whole lot of use.
The only type of printer file that should be readable by another program would be anything that was printed to a postscipt file. There are a couple of shareware programs like Ghostscript which can view postscript files.

Thanks one and all, it is bad form to request help and then not respond to those that are offering same.  In my case a family emergency has and will keep me away from email for awhile at least.  I have a situation where the program I use complies text and graphics to a printer.  I'm hoping to be able to edit before the material is printed.  The Ghostscipt and Ghost Edit look promising to edit the "prn" files that result from the print to file.  I'll have to work with this in the future but at this point I can't get either to open the "prn" file in a way that I'm able to see, much less edit, the graphics or text.  
Sending the compilation to a fax program also sound like it has promise and I will follow up on same.
Again thanks for the responses, I'll get back to it when I can.