What files control the process initiation, exactly.

[Uber Jiminy]

I am kind of confused as to what files do what. I know /etc/inittab controls runlevel, and runs some scripts, and whatnot, but what about /etc/init.d/, or /etc/rc1.d, or /etc/rc2.d. What do these do? They all have lots of scripts in them..I was thinking that inittab runs one of the rcX.d's, depending on the runlevel of the bootup. Is this right? Like, runlevel 3 is going to run /etc/rc3.d. I could be rambling nonsensically, but, that's why I am here, right?

[Malakin]

What you said is correct. Those are for the different runlevels. Scripts starting with an S are startup scripts, ones starting with K are kill scripts. The files in the rcX.d directories are actually links to the scripts in /etc/init.d

[bdg1983]

And to add a little more info on the subject, try the short NHF on SysVinit (http://www.linuxnewbie.org/nhf/intel/osbooting/sysvinit.html).