Runlevels

There are 7 runlevels in a Linux. These runlevels determine how the system will start.

Runlevel 0 is used for system shutdown.

Runlevel 1 is a single user mode, with networking disabled. Runlevel 1 is used to troubleshoot issues.

Runlevel 2 is a multiuser mode, however networking is disabled.

Runlevel 3 is multiuser mode with no Graphical User Interface. GUI maybe useful for fancy graphics, however it may slow down the system, and may be not necessary for remote operations.

Runlevel 4: Not defined.

Runlevel 5: It is a multi user mode with Graphical User Interface enabled.

Runlevel 6: It is used for reboot of the system.

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