Which type of memory retains data even when powered off?

Non-volatile memory is designed to retain data even when the power is turned off. This type of memory is essential for long-term data storage, as it ensures that information is not lost when the device is powered down. Non-volatile memory includes various technologies such as flash memory, hard drives, and read-only memory (ROM).

In contrast, volatile memory requires power to maintain the stored information. Examples of volatile memory include dynamic random-access memory (DRAM) and static random-access memory (SRAM), both of which lose their contents when the power is removed. Dynamic memory, a specific type of volatile memory, requires continuous refreshing to maintain data integrity. Static memory, while it can retain data longer than dynamic memory, still falls into the volatile category.

Non-volatile memory's ability to store data permanently makes it indispensable for devices that need to save user data and system states, allowing for restoration of applications and files once the device is powered back on.