System V method of initialization is one of the most widely used across most Linux
distributions. It definitely eases the system administrators job. There's a lot more than
autoexec.bat and config.sys here. We've written this article for novice users. It explains
the concept of runlevels, initialization scripts and the significance of /etc/rc.d.
In the traditional BSD style of startup, there are only a few initialization scripts, which are
something like the autoexec.bat and config.sys pair of DOS. Commands are executed
and services are loaded up sequentially as given in the scripts. From FreeOS.com.