What are ...EXE Files ???---Help Please!!!

[HOLTG@CTRVAX.VANDERBILT.EDU]

My name is Gayle Holt,

Could someone out there please explain what GS/OS Shell Applications are???
Also, how do I use them???---I just recently downloaded UNZIP for the ][gs 
at GRIND.ISCA.UIOWA.EDU, de-BINSCIIed it, and the file is not a regular 
application.----When I go to icon info in the Finder, it tells me that this 
file is a GS/OS shell application...

Thanks for any help!!!

Gayle Holt
internet:  holtg@ctrvax.vanderbilt.edu