Standard semantics of Runlevels
These vary by distribution, so this is an incomplete list of the most common distributions. If you have additional distributions, please email the author and have the information added to this manual.
	
Runlevel 0: 	 halt (shuts down the machine)
Runlevel 1: 	 Single user mode.
Runlevel 2: 	 Multi user text only, without NFS.
Runlevel 3: 	 Multi user text-only, with full networking.
Runlevel 4: 	 Not used.
Runlevel 5: 	 Multi user X11 with full networking.
Runlevel 6: 	 Reboot