how does a system come up if you disable background fsck ?

[Ensel Sharon]

I have disabled background fsck in my /etc/rc.conf with:

background_fsck="no"

But I am curious - what does this mean for the system if the system
crashes ?

Does this mean that the system will wait for all non root partitions to
fully fsck before coming up into multi-user mode ?

OR

Does it mean the system will boot up quickly into multi-user mode, but the
non-root partitions will just not be mounted and/or usable until I fsck
them by hand ?

thanks.