confusion of installation process

[Darshak]

Hi, all
     I m new to linux. I have some doubts
When installation begins , initrd is loaded by ISOLINUX. then kernel is 
loaded.which runs linuxrc script linuxrc mounts cdrom then /sbin/loader 
is run.

Then monitor and all done by anaconda.


But when I choose installation from harddrive then it asks for location 
of ISO. and then checks that proper ISO is there or not .
Is this done by anaconda ? OR by linuxrc ?  I m not aware ?       :(
then how is it done ?


Thanxs
Darshak