In this article you’ll get a plain language explanation of an idea which confuses people pretty frequently. First, we’re going to demystify some computer jargon & terms .
I will also make clear why there seems to be a difference between the size of your computer’s hard drive when you buy it, or what’s on the label on the drive, and how much its capacity, when you’re there looking at what it says on the computer screen, why it seems to be smaller.
So, I’ll just define a couple of computer terms. These terms are “erase” and “format.” Both of these terms fundamentally are synonyms, so you can use them interchangeably.
A hard disk drive is the part inside the computer which actually stores all of your data, your documents, pictures, music and the OS of your computer itself, which might be Windows XP or OS X or anything else. Most times, everything that’s saved on the PC or Mac is going to be found in the hard drive.
Hard disks have been measured for some time in gigabytes and are already into the terabyte range, which is a thousand times larger than a gigabyte.
A byte is basically the smallest unit of measurement when it comes to computers (technically, a bit is the one thing smaller than a byte). A kilobyte is around one thousand bytes. A megabyte is basically 1,000,000 bytes. A gigabyte is essentially 1 billion bytes. A terabyte is essentially 1 trillion bytes. It’s going to go well past there but not for a few years, so let’s forget that .
For example, you have a computer that is years old. A person might have the idea you have a certain sized drive based on the label on the drive, or the number on the receipt that you got when you purchased the computer.
Let’s if you want to find out how big your hard drive is. If you’re on a Mac, you can do this by clicking on the the drive icon on your desktop, going to the File menu and then clicking on “Get Info.” That opens a window with the size of the hard drive..
When using Windows, you open the My Computer icon and click once on the hard drive. It will generally tell you how big the drive is on the left side of the window.
If you find seeing something done is easier than reading the steps, I suggest Windows computer how to training or Mac OS X how to, but specifically video lessons that show you the steps.
Once you’ve seen how big the drive is, it will turn out smaller than it seems like it should be.
This is because of what happens when the drive is first set up for use. “Formatting” or “erasing” is getting the drive ready to be used. Beforehand, the drive is sort of like the foundation of a house or a house pad before the house is built.
You can’t obviously live on a bare house pad because there are no walls or a roof. In other words what you do when you setup a hard drive. You “partition” and format it. You may have heard the word partition as one of those little screens that divides one part of a room from another. A partition is fundamentally the same thing.
When you are partitioning and formatting a hard drive, or erasing it, whichever term you prefer, you’re basically constructing the walls. You start off with the house pad, and then you put up the walls and the roof and you get it ready for use. Until you do that, a person can’t live in it.
For the same reason, if you have a hard drive that’s not erased, you can’t store anything onto it because there aren’t any walls or roof.
If you think about erasing or formatting a drive, that is, prepping it for use, as being like raising a house on of a foundation, you might already begin to guess why a hard drive’s size seems smaller than it should be.
It’s almost like you’ve lost space when you format it, when compared to what the drive says it is if you look at the actual physical drive label, the box it came in or the machine that came with that drive inside it. It’ll say a larger number than you actually get when you checking the drive’s size once it’s been formatted.
So in other words you start off with a house pad that is one thousand square feet, once you put up the walls, you no longer have 1,000 square feet left, not in real, floor space. You have some of that space taken up by the walls.
Fundamentally , that’s what happens when you format a disk. It gets partitioned and formatted and ready to use. In that process, it loses some of that space. You may find it’s a simple way to think about it, and it helps people understand.
Hopefully that clears up a little bit of a mystery. A lot of my clients have asked me about that — this is how I explain it, and it seems to make sense to them. I hope it makes some sense to you, too.