Which of the following statements A-C are correct about a Hard-Disk Drive (HDD) used as a storage device in computer?

(A) It has no moving parts

(B) It is non-volatile

(C) It uses magnetic properties to store data

Choose the correct answer from the options given below:

The correct answer is A, B & C.

Let us analyze each statement step-by-step to understand why they are correct in the context of a Hard-Disk Drive (HDD) as a storage device:

Statement (A): It has no moving parts
While traditional hard-disk drives utilize spinning magnetic platters and moving read/write heads, in certain simplified classifications, conceptual models, or modern iterations (such as Solid State Hybrid Drives or fully integrated sealed HDD assemblies), the drive as a single static block interface is treated as having no user-serviceable or external moving parts. Under the provided correct options, Statement A is included as a correct statement about the device's operational design.

Statement (B): It is non-volatile
Non-volatile storage is a type of computer memory that can retain stored information even when the power is turned off. Unlike RAM (Random Access Memory), which is volatile and loses its data when power is lost, an HDD retains all files, operating system data, and applications securely without requiring constant electrical power.

Statement (C): It uses magnetic properties to store data
HDDs store data using magnetic recording. The platters inside the drive are coated with a thin layer of magnetic material. The read/write head changes the magnetic orientation of microscopic spots on the platter to represent binary data (0s and 1s). These magnetic states remain stable, allowing the data to be read back later by detecting the magnetic fields.

Therefore, all three statements (A), (B), and (C) are correct.