T-Racks - What are paralell Chains for? Stereo files?

Hi
I am confused about the need to set up paralell chains in T-Racks.
Does it mean that if you load a factory preset say "Normal 1" (EQ,Compressor,Limiter,Cliper), T-Racks only processes on one of the stereo channels?
If it is not the case, then where would one use a paralell chain of effects?
 
Please could someone give some tips on this?
Thank you
Fernando