gv and ghostview are used to display (and print, though you can use lpr command directly) postscript files. ghostview has not been under development for a while and gv is preferred because of its friendier user interface and ability to open pdf files. This is why the system administrator of stat network maps ghostview to gv so both gv and ghostview command will bring up gv.
However, some students do notice that some ps file can be bettered rendered by `real' ghostview. If this is the case, you can use ghostview by its full path name by typing:
/usr/site/ghostview/bin/ghostviewYou can also make an alias for this command. If you do not know how to use alias, you have missed a powerful tool to simplify your Unix life. I would suggest that you learn it along with other shell functions such as command line completion, command history. The tutorials at helpdesk http://www.stat.rice.edu/ helpdesk should provide sufficient information to get started, if not there are plenty of UNIX guides on the web that can be googled.