Which type of memory retains data even when the computer is turned off?

Non-volatile memory is designed to retain data even when the computer is powered down. This permanence is crucial for storing important data like operating systems, applications, and user files that need to be preserved across power cycles. Examples of non-volatile memory include flash memory, hard drives, and SSDs, all of which save configurations, documents, and other information regardless of whether the device is on or off.

In contrast, RAM and volatile memory do not retain data once power is lost because they rely on electrical charge to store information temporarily. Cache memory, while a type of RAM utilized for speeding up data access by holding frequently used information, is also volatile and therefore unable to maintain its data without power. This distinction clarifies why non-volatile memory is the correct answer for maintaining data during power outages or shutdowns.