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Just What Is a Backup, Anyway?

Something so many people overlook.

Backup Flash Drive

At its most basic, backups are simple: a copy of something kept somewhere else to keep it safe.
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Backing up is incredibly important, and it’s something I harp on a lot.

It also confuses many people with its esoteric terminology and concepts.

Let’s tackle the most fundamental term of all: backup.

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What is a backup?

A backup is an additional copy of your data, or your entire system, saved elsewhere. The futher “elsewhere” is from the original, the more things the backup can protect you from.

Backup basics

A backup is very simple: it’s a copy — a copy of a file, of your data, of a computer, of an operating system, of anything or everything.

Remember this phrase:

If there’s only one, it’s not backed up.

Or as I sometimes put it:

If it’s in only one place, it’s not backed up.

By that, I mean if you have only one of something — call it the original, if you like — and something happens to it, it’s gone forever. If a hardware failure, malware, account hack, or similar scenario takes away that one and only copy, it’s gone.


That’s why I harp so much on backing up.

So backing up is nothing more than making a copy of something — and putting it somewhere for safekeeping.

Backup locations

Almost as important as making a backup is where you put it.

When we back up, we make a copy somewhere else. “Somewhere else” is open to interpretation depending on what you’re doing, but the important thing is that if you make a copy of something, you’re backed up, and the further away from the original that copy is, the more protected it is.

For example, if you’re working on a word processing document, you might:

  • Click on Save to copy what you’re working on to disk.1


  • Click on Save As and save the file with another name; this will copy what you’re working on to disk without overwriting what you started with.

Those types of actions protect against certain types of failures that would otherwise lose your work — for example, application crashes, changes you make by mistake, or even accidentally deleting the file.

They’re not, however, going to protect you from things like hard disk failure or malware. Moving your backup further away from the original location protects you from more threats.

  • Storing it on an external drive protects you from a variety of hardware and software failures on your computer.
  • Storing it on an external drive you then disconnect and keep in your desk drawer protects you from all that plus malware that might attempt to harm data on external drives (such as some variants of ransomware).
  • And, of course, storing it online or on a disk in a bank vault protects you from all that and more, including your house burning to the ground.

Each is conceptually and often physically a little more removed from the previous location.

Back up or backup?

And finally one little clarification:

Is it backup or back up?

This is something that my editor catches in my writing frequently.

Backup is a noun or adjective. A backup is a thing. I have a backup or a backup copy or a backup of my hard disk.

Back up is a verb. To back up is to take an action. I make a backup (thing) by backing up (action).

So a backup is the thing you’re trying to create, and backing up is what I’m encouraging you to do.

Do this

Start backing up, if you haven’t already, and review that your backup is working and covering everything you expect if you have.

Then, subscribe to Confident Computing! Less frustration and more confidence, solutions, answers, and tips in your inbox every week.

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Footnotes & references

1: You can often tell how “experienced” a computer user is by how much of a habit they have of pressing the “Save” shortcut, typically CTRL+S, as they work.

9 comments on “Just What Is a Backup, Anyway?”

  1. Good article! Short and concise!
    Don’t forget that the “cloud” is an option for backups as well.
    I have my data backed up that way nightly and it’s comforting to know that I have an off-site backup of my data, current, in case I should need it.

  2. I was storing all on a USB — now that it was brought to my attention that USB’s wear out and if the house caught on fire I wouldn’t have it. Question, How do I get the contents of the USB on cloud? I definitely am not computer savvy and would like to learn.

    • If you are referring to a USB thumb drive, those are not a good medium for backing up. Flash drives are only good for temporary storage such as moving files from one device to another or working on one of your files on someone else’s machine.

      If you keep a copy of your user files in a OneDrive, Dropbox, Google Drive folder, they will be synced with the servers of that cloud storage provider. The transfer speed of cloud storage is so slow that it would be impractical to upload a system image backup to the cloud. To protect your system from fire and other disasters, you can swap out your backup drive and keep a copy at work or at a friend or relative’s house. Most backup programs allow you to encrypt your backup. I recommend that for any backups away from home and it’s also a good idea to encrypt local backups.

  3. So much reading Leo, I just need to know where do I post a couple of basic questions? All I want to know is should I use a Flash drive or DVD? And can I use a flash drive that already has been used before? Do I need to erase everything that’s already on it?



    • I recommend an external hard disk. DVDs are typically too small, unless you’re only doing data. Flashdrives are typically also too small, but may also not hold the data as long as they’re typically cheap. Whether or not you need to erase depends on the backup software you’re using and how much space you have and need. If you can, there’s no harm in erasing first.


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