Following are the run-levels which you could refer:
0 — Halt
1 — Single-user mode
2 — not used (user-definable)
3 — full multiuser mode
4 — not used (user-definable)
5 — full multiuser mode (with an X-based login screen)
6 — Reboot
If you use a command line login screen, then you are in run level 3.
If you use a graphical login screen, you are operating in run level 5.
The default run level can be changed by editing the /etc/inittab file.
It contains a line near the top of the file similar to the following:
Change the number in this line to the desired run level.
You will have to reboot the system for the changes to take effect.