set-o的结果倒是什么意思啊？

tracydundun@tracydundun-laptop:~$ set -o
allexport off
braceexpand on
emacs on
errexit off
errtrace off
functrace off
hashall on
histexpand on
history on
ignoreeof off
interactive-comments on
keyword off
monitor on
noclobber off
noexec off
noglob off
nolog off
notify off
nounset off
onecmd off
physical off
pipefail off
posix off
privileged off
verbose off
vi off
xtrace off
这上面的OFF 和 ON是指什么阿？比如vi off这一行，off代表什么被关闭？在off的情况下我也能用vi进行文件编辑啊/
请各位指教！！