Understanding run levels

There are seven run levels. The system will be started in run level 1 to 5. Run level 0 is used for shutting down the system. Run level 6 is used for rebooting the system. The graphical user interface is started in run level 5. The following is the summary of the different run levels:

Sr. No.

Run level number

Description

1

0

Halting the system

2

1

Single-user mode

3

2

Multi-user mode

4

3

Multi-user with network support

5

4

Not used

6

5

Graphical user interface with multi-user and networking support

7

6

Rebooting the system

 

We need to be in the root-user mode to use the init command.

If we give the following command, then the system will shut down: ...

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