Hard disk storage is known as __________ storage.

• A. volatile
• B. RAM
• C. primary
• D. secondary

Answer: (D)

Hard disk storage is known as secondary storage. The main idea is the way computers separate memory into tiers: primary storage (RAM) is fast and volatile, used for data the CPU is actively working with, and loses its contents when power is removed. Secondary storage, like hard disks, is non-volatile and holds data long-term, retaining programs and files even when the device is off. Because a hard drive stores data persistently but is slower to access than RAM, it belongs in the secondary storage category rather than primary. The other terms don’t fit: RAM is volatile main memory, primary storage refers to that active memory, and non-volatile storage is a broader trait not a separate category by itself.