Some basic services are running but networking is disabled. SuSE works this way and makes the distinction between the two runlevels. 2,3,4 and 5 can be customized to your liking. Red Hat, for example, uses runlevel 5 when starting the GUI after boot. There's nothing stopping you from changing this setup to a custom configuration of your liking.
Some distributions do divert and do things differently here.
We'll first look at Red Hat and then look at the SuSE structure in this article. The scripts, which are simple shell scripts, generally offer some very useful functions that are given as command line arguments. Stop the service restart - Stop the service and restart it. You will see something like the extract below. You should also take note of the naming scheme of these symlinks.