Storage which retains data after power cut off is called.

The type of storage that retains data even when the power is turned off is called non-volatile storage. Non-volatile storage is different from volatile storage, which loses all data when the power is turned off. To help you understand the difference, imagine that you have two types of memory: a whiteboard and a notebook. The whiteboard is like volatile memory because anything you write on it will disappear as soon as you erase it or turn off the lights. On the other hand, the notebook is like non-volatile memory because anything you write in it will remain there until you deliberately erase or destroy it. Similarly, non-volatile storage, such as hard drives, solid-state drives (SSDs), and flash drives, can retain data even when the power is turned off. This is because the data is stored using physical means that do not require an electrical charge to be maintained. In contrast, volatile storage, such as RAM, loses all data when the power is turned off because the data is stored using electrical charges that require a constant supply of power to be maintained. Overall, non-volatile storage is essential for long-term data storage because it can retain data even in the absence of power, whereas volatile storage is useful for short-term storage of data that does not need to be preserved beyond the current session or power cycle.