What type of memory is used primarily for data storage that does not change?

The correct answer is ROM, which stands for Read-Only Memory. ROM is a type of non-volatile memory, which means it retains its data even when the power is turned off. It is primarily used for storing firmware or software that is not expected to change during the normal operation of a device. This makes it ideal for storing essential instructions required for booting up hardware and performing low-level tasks.

While EEPROM and RAM have their specific applications, they do not fit the criteria as well as ROM does in terms of data that does not change. EEPROM (Electrically Erasable Programmable Read-Only Memory) is a type of non-volatile memory that can be reprogrammed and rewritten, making it suitable for applications where data might need to be updated occasionally. RAM (Random Access Memory), on the other hand, is volatile memory that loses its contents when power is cut off and is primarily used for temporary data storage during operation. Cache memory is also volatile and serves to speed up access to frequently used data but does not provide persistent storage like ROM. Thus, ROM stands out as the primary type of memory used for stable, unchangeable data storage.