A hard disk drive (HDD), hard disk, hard drive, or fixed disk, [b] is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material.

A hard disk drive (HDD) is an internal or external computer component that stores data, such as the operating system, applications, and user files. HDDs are “non-volatile” storage devices, meaning they retain stored data even when power isn't being supplied.

A hard disk drive (sometimes abbreviated as a hard drive, HD, or HDD) is a non-volatile data storage device. It is usually installed internally in a computer, attached directly to the disk controller of the computer's motherboard. It contains one or more platters housed inside an air-sealed casing.

A computer’s hard drive is a device consisting of several hard disks, read/write heads, a drive motor to spin the disks, and a small amount of circuitry, all sealed in a metal case to protect the disks from dust.

What is a Hard Disk Drive? A hard disk is a memory storage device that looks like this: The disk is divided into tracks. Each track is further divided into sectors. The point to be noted here is that outer tracks are bigger in size than the inner tracks but they contain the same number of sectors and have equal storage capacity.