What is a Hard Disk Drive?

Everything You Need to Know About Computer Hard Drives

A 2.5
Evan Amos/Wikimedia Commons/Creative Commons 3.0

The hard disk drive is the main, and usually largest, data storage hardware device in a computer.

The operating system, software titles, and most other files are stored in the hard disk drive.

The Hard Disk Drive is Also Known As

HDD (abbreviation), hard drive, hard disk, fixed drive, fixed disk, fixed disk drive

Important Hard Disk Drive Facts

The hard drive is sometimes referred to as the "C drive" due to the fact that Microsoft Windows designates the "C" drive letter to the primary partition on the primary hard drive in a computer by default.

While this is not a technically correct term to use, it is still common. For example, some computers have multiple drive letters (e.g. C, D, E) representing areas across one or more hard drives.

Popular Hard Disk Drive Manufacturers

Seagate, Western Digital, Hitachi

Hard Disk Drive Description

A hard drive is usually the size of a paperback book but much heavier.

The sides of the hard drive have pre-drilled, threaded holes for easy mounting in the 3.5-inch drive bay in the computer case. Mounting is also possible in a larger 5.25-inch drive bay with an adapter. The hard drive is mounted so the end with the connections faces inside the computer.

The back end of the hard drive contains a port for a cable that connects to the motherboard. The type of cable used will depend on the type of drive but is almost always included with a hard drive purchase. Also here is a connection for power from the power supply.

Most hard drives also have jumper settings on the back end that define how the motherboard is to recognize the drive when more than one is present. These settings vary from drive to drive so check with your hard drive manufacturer for details.

Common Hard Disk Drive Tasks

Here are some common things you might do that involve a hard disk drive: