Ghostscript is an interpreter for the PostScript page description language used by laser printers. This application does more than display postscript files, you can extract text from .ps files, and print ps files. You can even view PDF files with GSView. You will not likely need Ghostscript unless you are planning to write script code for viewing in Ghostview.
Postscript is a very versatile printer description language.
One of the neatest things you can do is print more than one logical page per physical page. On the CPSC undergrad systems, the utility for doing this is called psnup . You pass in a postscript file, and tell psnup how many logical pages per physical page, and it outputs another postscript file that you can print. Here's an example output of a2ps and psnup . However, there are ways to do the same thing.