exit

Cause the shell to exit.

Syntax
      exit [n]

Key
   n   Set the exit status to n

If n is omitted, the exit status is that of the last command executed. A trap on EXIT is executed before the shell terminates.

exit is a bash built in command.

“An exit strategy is a means of escaping one's current situation, typically an unfavourable situation” - Wikipedia

Related:

screen - Multiplex terminal, run remote shells via ssh
shutdown - Shutdown or restart OS X