Which type of memory retains data without power?

Read-Only Memory (ROM) is the type of memory that retains data without power. This non-volatile memory is used primarily to store firmware or software that is closely tied to the hardware of a device. Since it does not lose its contents when the power is turned off, it is essential for boot processes and other fundamental functions that need to be available immediately upon power-up.

In contrast, Random Access Memory (RAM) and cache memory are both types of volatile memory, which means they lose their data when power is removed. Virtual memory, on the other hand, is a memory management capability that creates the illusion of a larger amount of RAM by using disk space to extend available memory but also loses its data when the system is powered down. Understanding the characteristics of each type of memory is crucial for grasping how computers store and manage data.