Which storage device retains data even when the computer is powered off?

The hard drive is a storage device that retains data even when the computer is powered off due to its design and functionality. Unlike volatile memory types, such as RAM and cache memory, which lose their data when the power is turned off, the hard drive stores data on magnetic or solid-state media that is persistent. This means that any files, applications, or system information saved to the hard drive will remain intact until deleted or modified, regardless of the computer's power state.

The USB drive also retains data when not powered, offering a portable means to store and transfer files. However, the focus of the question is on storage devices that can hold large amounts of data within the computer system, where the hard drive plays a major role. In contrast, RAM and cache memory serve as temporary storage areas to facilitate quick access to data while the computer is running, but both will lose any stored data upon shutdown.