noun

HDD

aitch-dee-DEE

HDD (noun) means a storage device that records data magnetically on rapidly spinning metal or glass discs, read and written by an arm that moves across their surface, and that keeps its contents when the power is off. Example: “The old HDD made a faint clicking noise every time a file was saved.”

noun

A storage device that records data magnetically on rapidly spinning metal or glass discs, read and written by an arm that moves across their surface, and that keeps its contents when the power is off.

"The old HDD made a faint clicking noise every time a file was saved."

"She archived the footage onto a four-terabyte HDD."

How to Use HDD

Learner’s notes

In plain EnglishAn older kind of storage that saves your files on spinning discs.

When to use it

HDD is the retail and specification term; in speech people usually say hard drive.

Memory tip

In conversation hard drive is often used loosely for any internal storage, including SSDs.

Trace the full origin ↓

Easily confused with

SSD → RAM → NAS

Common pairings

external HDD internal HDD HDD capacity 7200 RPM HDD

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Fill the Gap

Can you complete this real example?

The old _____ made a faint clicking noise every time a file was saved.

Etymology

An initialism of hard disk drive.

Origin: English

Synonyms

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hard disk drive hard drive hard disk spinning disk mechanical drive

Antonyms

SSD solid-state drive

Related Words

SSD

Frequently Asked Questions

What is the difference between an HDD and an SSD?

An HDD has moving parts: platters that spin and a head that swings across them to find data, which takes time and makes noise. An SSD uses flash memory chips with nothing moving, so it responds far faster. HDDs generally give more storage per pound spent.

Is a hard drive the same as memory?

No. A hard drive is storage and keeps files after the machine is switched off. Memory usually means RAM, which is temporary working space that is wiped when the power goes. Confusing the two is one of the most common mix-ups in computing.

Why are HDDs still sold?

Because they remain cheaper per terabyte than flash, which matters for backups, media libraries and data centres where capacity counts for more than speed.

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