How is normal ROM programmed
I assume ROM and MROM are two different things


You assume incorrectly. "ROM" is just an umbrella term that can be used to refer to any type of memory that cannot be modified after the device has been manufactured. If not otherwise specified, it usually refers to mask ROM, but it can also refer to other technologies which behave the same way, like PROM/EPROM devices or flash memory with writes disabled.