Which type of memory is often referred to as non-volatile?

The type of memory referred to as non-volatile is ROM, which stands for Read-Only Memory. This kind of memory retains its data even when the power is turned off, making it essential for storing firmware and other critical information that must be preserved across power cycles.

Non-volatile memory is crucial in systems where data integrity and availability after a power loss are needed. For example, ROM contains the instructions for booting up the computer and performing hardware initialization, ensuring that the system can start operating correctly each time it is powered on.

In contrast, RAM (Random Access Memory) is volatile, meaning it loses all stored information when the power goes off. Cache memory and registers are also types of volatile memory, primarily used for temporary storage during active processes. Thus, ROM is the definitive non-volatile memory type among the options listed, as it maintains its data without a continuous power supply.