ShellScript is a ["Script"] written for the ["Shell"] (["Bash"]). They are similar to *.bat files in Windows.
The ["MIME"] type is application/x-shellscript
They are text files which first line says the shell to use (bash). So the first line is
Including this line, Debian knows this is a shell script (they don't need to finish with *.["Sh"]).
After this, you can include comments using # in the beginning of the line. For example:
#This is a comment.
/bin/sh is its interpreter.
Finally, see the ["Bash"] commands.
[http://steve-parker.org/sh/sh.shtml Linux Shell Scripting Tutorial].
[http://www.zazzybob.com/bin.html Shell Script Repository].