In memory terminology, storage that retains data even after the computer is powered off is referred to as what type of storage?

Introduction / Context:
Computer systems use different kinds of memory and storage, some of which keep data only while power is on, and others which preserve data permanently or semi-permanently even when power is switched off. Understanding the distinction between volatile and non-volatile storage is fundamental for explaining why programs and files must be saved to disk and cannot remain only in RAM.

Given Data / Assumptions:

• The question refers to storage that retains data after power is turned off.
• The options include volatile storage, non-volatile storage, sequential storage, and direct storage.
• We assume standard definitions of RAM and secondary storage devices.
• Volatile storage loses data when power is removed, while non-volatile storage does not.

Concept / Approach:
Volatile storage, such as typical main memory (RAM), requires continuous power to maintain stored information. When the computer is shut down, data in volatile memory is lost. Non-volatile storage, such as hard drives, SSDs, flash drives, and ROM, retains information even when there is no power. Sequential and direct describe access patterns, not whether data is retained after power loss. Therefore, storage that keeps data after power off is called non-volatile storage.

Step-by-Step Solution:
Step 1: Recall what happens to data in RAM when a computer shuts down. Data in RAM is erased because RAM is volatile. Step 2: Recall what happens to files saved on a hard disk or flash drive. These files remain available even after shutdown, indicating non-volatile storage. Step 3: Match this behaviour with the terminology. Storage that keeps data without power is called non-volatile; storage that loses data without power is called volatile. Step 4: Evaluate the other two terms. Sequential and direct refer to how data is accessed, not whether it is retained. Step 5: Select “Non-volatile storage” as the correct answer.

Verification / Alternative check:
Computer architecture texts clearly define volatile memory as memory that does not retain its contents when power is removed, citing RAM as the main example. They define non-volatile memory to include ROM, flash memory, and magnetic or solid state storage devices that preserve data across reboots. Storage types such as hard drives and SSDs are described as non-volatile because they store operating systems and user files that must remain available. Sequential storage refers to devices like magnetic tape, and direct access refers to devices like disks; both refer to access modes, not power dependence. This confirms that non-volatile storage is the correct term.

Why Other Options Are Wrong:
Option A (Volatile storage): Loses its contents when power is turned off, so it cannot retain data after shutdown. Option C (Sequential storage): Describes access pattern where data is read in sequence, as on magnetic tapes, not persistence after power off. Option D (Direct storage): Refers to direct or random access to data (as on disks), again not to power dependence.

Common Pitfalls:
Students sometimes mix up volatile and non-volatile because the term “volatile” sounds stronger and might be misinterpreted. Others confuse access patterns such as sequential and direct with data retention properties. To avoid these errors, remember this simple rule: if data survives a power off, the storage is non-volatile; if it disappears on power off, it is volatile.

Final Answer:
Storage that retains data after power off is called Non-volatile storage.