Read Only Memory (ROM) is non-volatile. What does it mean by non-volatile?

Information in Read Only Memory (ROM) & Programmable Read Only Memory(PROM) cannot be erased and can only be programmed once.

Information in Erasable Programmable Read Only Memory (EPROM) & Electrically Erasable Programmable Read Only Memory (EEPROM) can be rewritten.

GDDR RAM is used in graphics cards, while your computer's CPU uses DDR SDRAM.

Static RAM is much faster than DRAM but it is more expensive than DRAM. Therefore it is mainly use in graphics card.

Which is not an Error Checking Method used in Random Access Memory (RAM)?