Global Startup Scripts
After the default runlevel has been set,init(via/etc/inittab) then runs the following scripts:
/etc/rc.d/rc.sysinit- handles system initialization, file system mount and check, PNP devices, etc.
/etc/rc.d/rc X -whereX_is the runlevel passed as an argument by_init. This script then calls the specified script for the runlevel that is being started.
/etc/rc.d/rc.local- called from within the specific runlevel scripts,rc.local_is a general purpose script that can be edited to include commands that you want started at bootup (sort of like_autoexec.bat).
Again, this is somewhat Red Hat / Mandrake specific. Other distributions can differ slightly (some differ greatly!), but the concept remains consistent. Once you become familiar with the process, it will make sense. The ability to manipulate startup scripts is an important step in your Linux learning process.