runlevel - Defines what run levels the process is valid for. AIX uses run levels of
0-9. If the telinit command is used to change the runlevel, a SIGTERM signal is
sent to all processes that are not defined for the new run level. If, after 20 seconds,
a process hasn't terminated, a SIGKILL signal is sent. The default run level for the
system is 2, which is AIX multiuser mode.