hard disk drive
The mechanism that reads and writes data on a hard disk. Hard disk drives (HDDs) for PCs generally have seek times of about 12 milliseconds or less. Many disk drives improve their performance through a technique called caching.
Hard disk drives are sometimes called Winchester drives, Winchester being the name of one of the first popular hard disk drive technologies developed by IBM in 1973.
See What's Inside a Hard Drive? in the Did You Know ... ? section of Webopedia.
Also see Formatting a Hard Disk Drive in the "Did You Know...?" section of Webopedia.
Also see Learn How to Defrag Your Hard Drive in the Did You Know...? section of Webopedia.
Also see "Tips to Fix a Slow Running Computer" in the Quick Reference section of Webopedia.