# Understanding Hard Drives: Storage Essentials
A hard drive (HDD) is a fundamental storage device used in computers and other electronic systems to store and retrieve digital data. It consists of spinning magnetic disks (platters) read by a moving arm with a read/write head.
## How It Works
HDDs store data magnetically on rotating platters. When the computer requests data, the drive spins the platters and the head accesses the information. Speed is measured in RPM (Revolutions Per Minute), with common speeds being 5400 RPM (slower, energy-efficient) and 7200 RPM (faster performance).
## Key Features
– Capacity: Ranges from 500GB to multiple terabytes (TB).
– Durability: Sensitive to physical shocks due to moving parts.
– Cost: Cheaper per gigabyte compared to SSDs (Solid State Drives).
## HDD vs. SSD
While HDDs offer high storage at low cost, SSDs (which use flash memory) are faster, quieter, and more durable but pricier. Many users combine both—using an SSD for the operating system and an HDD for bulk storage.
## Conclusion
Hard drives remain a cost-effective solution for high-capacity storage, though SSDs are gaining dominance in speed-critical applications. For backups, media storage, and budget builds, HDDs continue to be a reliable choice.
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