kvm:the difference between "blacklist" and "softdep"

I am newbie here and I can only find the blog or readme from github. Is there any official documents? Emm,someone wrote the "blacklist" on "/etc/modules-load.d/modules.conf" while someone wrote the "blacklist" on "/etc/modules-load.d/blacklist.conf". And someone wrote the "softdep" instead of "blacklist" For example, someone wrote echo "blacklist nouveau" >> /etc/modprobe.d/blacklist.conf echo "blacklist nvidia" >> /etc/modprobe.d/blacklist.conf echo "blacklist radeon" >> /etc/modprobe.d/blacklist.conf echo "blacklist amdgpu" >> /etc/modprobe.d/blacklist.conf echo "blacklist nvidiafb" >> /etc/modprobe.d/blacklist.conf echo "blacklist snd_hda_intel" >> /etc/modprobe.d/blacklist.conf and someone wrote echo "softdep nouveau pre: vfio-pci" >> /etc/modprobe.d/nvidia.conf echo "softdep nvidia pre: vfio-pci" >> /etc/modprobe.d/nvidia.conf echo "softdep nvidia* pre: vfio-pci" >> /etc/modprobe.d/nvidia.conf I really don't know the difference,any suggestion would be appreciated.