Ever Wonder
Exactly, What is a Hard Drive?

Rotating magnetic platters in an aluminum case defines "what is a hard drive." The hard disk drive is one of the few moving parts in the modern computer. That it has moving parts is its greatest weakness but it makes up for it by providing a large amount of random access storage at a cheap price.

The terms Hard Drive and Hard Disk are often used in place of the more definitive term of Hard Disk Drive (HDD). Naturally, the abbreviated terms are not technically correct but they are easier to say and their use rarely results in any confusion.

In 1973, IBM introduced the model 3340 hard drive. This disk was the predecessor of modern sealed hard drives. Interestingly, IBM engineers gave this disk the code name of Winchester. The name stuck and hard drives were also called Winchester disks well into the Nineties. The highlights of the Winchester disk technology, which is still in use today, are the sealed disk, the lubricated platters, and the floating heads.

In 1980, Seagate introduced the 5MB ST-506 hard drive for microcomputers. This Winchester disk fit into the 5.25-inch full-height drive bay. From then on, the hard drive continued to shrink in size.

Physically, what is a hard drive?

• sealed aluminum case with a filtered air vent
  
  
• platters covered with a thin film of magnetic material
  
  
• spindle and spindle motor
  
  
• read and write heads
  
  
• actuator assembly to position the heads
  
  
• electronics used to move the actuator and read and write the data
  
  

Read more about Hard Drive Technology.

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