Intel BiosGuard?

The Gigabyte GA-H270N-WIFI motherboard has a setting called Intel BiosGuard in BIOS setup. I have tried to enable and disable it, but I’m not sure what it does. Almost all information found online is about BootGuard which is something else. What does Intel BiosGuard do and if enabled, does it make any permanent changes to the system e.g. programming the FPF? What happens if the setting is enabled after flashing a modified BIOS?