□ Run level : System operating mode
□ Run level config file : /etc/inittab
□ Current run level check command : runlevel
□ Run level change command : init [number]
□ [number]
○ 0 : System shutdown mode(=halt)
○ 1 : Single user mode
○ 2 : Multi user mode(No NFS)
○ 3 : Multi user mode
○ 4 : Unused
○ 5 : X Window mode
○ 6 : System reboot mode
○ 1 : Single user mode
○ 2 : Multi user mode(No NFS)
○ 3 : Multi user mode
○ 4 : Unused
○ 5 : X Window mode
○ 6 : System reboot mode