The Basic Parts of a Computer Hard Drive

Every computer has a hard drive, and most people are at least vaguely familiar with them. After all, it's basically the brain of a computer, and your average computer user has bought at least one or two of the things-some of us have even dealt with the dreaded hard drive crash.

However, most people don't know the basic parts of a hard drive and their function. By learning a bit about what makes up a hard drive, it can be easier to diagnose problems and understand how your computer operates. Here's a basic list of the most central parts of a hard drive and what they do.

Heads (or Head Stack Assembly)
The heads of a drive magnetically read and write data to the platters, moving at incredibly high speeds to extremely precise positions in order to do so. They're like the eyes of the drive, and float a very small distance from the platters--about a micron. If they come into contact with the platters, they can cause massive damage.

Spindle
The spindle-you guessed it-spins the platters of the drive under the heads. Modern spindles move between 4800 and 7200 rotations per minute, and in the future they're likely to go even faster in order to improve seek speed, which is the amount of time it takes the hard drive to find a certain area of data.

Platters
The platters hold the hard drive's information, and they're incredibly sensitive. Even a tiny speck of dust can render them useless, which is why a hard drive runs enclosed in the first place.

Some hard drives have more than one platters, while other have just one. When a drive has multiple platters, the spacing between them is also very precise, and if they're misaligned at all, the data on a drive is probably lost forever.

Electronics
The electronics board is the green circuitry on the bottom of the hard drive. They provide a connection with the rest of the computer and contain information known as firmware that tells the hard drive how to function. This firmware is different from drive to drive; for this reason, hard drives electronic boards with the same model number can't just be switched out.

These are just the basics of what makes up a hard drive, but by understanding what you're working with, you can make informed decisions when buying a new drive or diagnosing a problem with your old one.