Basic Input Output system. The BIOS for short is software that is installed onto the motherboard that enables the motherboard to be update and enables support of future products. The software on the motherboard is Electrically Erasable Programmable Read Only Memory, the act of erasing and programming the software is called flashing.
https://www.asus.com/us/Motherboards/PRIME-H370-A-CSM/HelpDesk_CPU/
I do not see any of the 9xxx series CPU's on the list, if the board supported them it would be listed here with the BIOS revision that enables their use