what is storage backup pictured as woman with laptop files streaming into cloud and multiple computers
It isn't enough to back up important files into one place (image by Microsoft Designer AI)

What is storage backup?

Storage backup means making a copy of the personal files stored on a computing device, for future reference and safekeeping. It may also include the operating system, applications and system settings.

It applies equally to home users and to business users, so we cover both here. This is especially noteworthy today as the lines blur between personal and business devices.

Recommended reading: Why storage backup is essential in 2024

Table of contents

We break this feature down into four key areas, but you can also jump to specific questions.

Broad questions about storage backup

Storage backup for businesses and personal computers

Practical questions about backups

What are the three types of backup?

Backup for mobile devices

Broad questions about storage backup

To start with, we cover the “big” questions about storage backup. These apply equally to home and business users.

What are the benefits of storage backup? 

As well as protecting your files from accidental loss, storage backup enables you to recover deleted documents that you later realise you should have kept – or, to check back to see how a document or spreadsheet looked on a previous date before the latest edits were applied.

What data should be backed up?

Anything that can’t be easily replaced should be backed up, such as documents, images and videos you’ve created or edited yourself. You might also want to back up some downloaded files, to save the bother of having to relocate them in the event of a computer crash. 

What is an example of a backup system?

A typical home backup system might automatically run every 24 hours, copying new and changed files to a local destination. There are backup features built into most operating systems that can handle this, plus plenty of free and commercial software options. Cloud backup services work similarly, using a custom agent to automatically upload files over the internet to a secure online storage repository.

Are backup and storage the same thing?

Backed-up files need to be stored somewhere – usually either on a physical storage device in your home, or in a cloud storage service. Ideally, they shouldn’t be stored in the same place as your working files, as we’ll discuss below.

Storage backup for businesses and personal computers

In this section, we cover the questions that individuals will ask – as well as what should concern IT teams within businesses. There is a lot of information on the web about storage backup for businesses, much of it written by vendors hoping to sell you something. Here, we attempt to provide unbiased answers to your questions.

Do I need storage backup?

Yes. Your computer hard disk probably holds many documents that you’ve created and edited yourself. In the event of a theft or hardware failure, these files could be lost forever – unless you have copies stored somewhere safe. If you don’t want to take that risk, you need storage backup.

What happens if you don’t back up your files?

Hopefully nothing. But if your computer breaks down and you don’t have backups of your files, the personal and professional loss could be considerable. If you do have backups you can simply copy them onto a different computer and carry on with your life. 

Should I back up my entire hard drive?

It’s not normally necessary to back up your operating system or application files – these can be reinstalled from public sources if need be. If you do back up your entire hard drive (sometimes called “imaging”), that gives you the ability to completely restore the working state of your system in the event of software failure.

Be warned, though, that complete drive backups can consume a lot of storage space, and if you need to replace a broken computer with a different model, your backed-up operating system may not work properly with the different hardware configuration.

What is a “321” backup system?

The “321” backup model means keeping three copies of all data, with backups on two different devices, one of which is offsite. A common way to achieve this is by backing up to both a local disk array and a remote cloud service. Though usually recommended for businesses, a “321” approach is worth considering for personal data, too, as it provides strong protection against all the most common data-loss scenarios.

Practical questions about backups

With the big questions covered, it’s time to turn to practical matters. What type of devices and services should you use? How do you actually put theory into practice?

What devices can be used to back up data?

Any storage device can be used for backups. In the past, tape cassettes, Iomega Zip disks and DVD-Rs have all been widely used. Today, the most popular destinations are a USB-connected hard disk or SSD; a network-attached storage array; a general-purpose cloud storage repository such as iCloud or Google Drive; or a dedicated cloud backup service such as IDrive, Backblaze, Carbonite or CrashPlan.

What is the best storage type for backup?

The common backup destinations each have pros and cons. USB storage is normally the fastest option for backing up, browsing and restoring files. The downside is that it has a fixed capacity, and in the event of a burglary or fire it could be lost along with the host system.

A NAS system is more extensible, and also more reliable if configured with multiple disks in a RAID array. It’s more expensive, though, and uploading and restoring files over a home network connection is normally slower than USB-attached storage. With cloud storage, capacity is effectively limitless, subject to your willingness to pay, and your backups are safe from almost any disaster. However, backing up and recovering files over the internet can be very slow.

What are the different types of backup location?

There are two types of backup location: onsite and offsite. Onsite backups are quick and convenient to access, but they’re not perfectly secure: as we’ve mentioned, if your home is burgled or burns down, you could lose your computer and your backup device too. Offsite backup is safer, but typically less convenient, slower to access and more costly to arrange.

How much backup storage do I need?

It depends on your needs. If you just need to protect a small number of important documents over a short period then a few hundred megabytes should be ample. If you want to keep a complete, long-term archive of all the files you access and download, including pictures, music and videos, it’s recommended to allow at least twice as much space as the computer’s hard disk. If you can stretch to four to eight times that capacity, you should be covered for several years. 

How often should you back up your data?

The short answer is “as often as is practical”. If you only back up your data once a week, a disaster could cause you to lose up to six days of work. Many cloud services back files up continuously, so your documents are protected seconds after you’ve finished editing them. If you’re managing your own backups, a good balance might be to back up your commonly used folders every night, with a full backup every week or month.

Can you delete backups to reclaim storage?

Backup archives naturally grow larger and larger over time, so whether you’re using your own hard disks or a remote cloud service, you may want to periodically purge your oldest backups to avoid running out of capacity. Remember that this may mean losing access to files that were deleted or changed a long time ago. And take special care if you’re using differential or incremental backups: you won’t be able to fully recover from these sets if you erase the full backups they’re based on.

What are the three types of backup?

A full backup is one common type of backup. A differential backup is a more efficient approach that stores only files that have changed or been created since your last full backup. This means you don’t waste time and storage archiving many duplicate copies of the same files. 

The third popular type is incremental backup. This is similar to differential backup, but each run only backs up files that have changed since the last incremental backup. Incremental backups can be individually very fast and compact, but to ensure that all files are recoverable it’s vital to retain a complete “chain” of incremental backups and the full backup they’re based on.

What are the advantages and disadvantages of a full backup?

A full backup is a complete copy of all the files contained on a device, often including the operating system and application files. A full backup allows you to conveniently browse and restore entire folders or computer systems from a single backup archive. The disadvantage is that backing up such large amounts of data can be slow, and consumes much more storage than a more selective backup. 

What’s the difference between a full backup and a mirror backup?

The term “mirror backup” is sometimes used to mean a full backup that includes the operating system and application files, as well as user data. Alternatively, it can refer to a current backup that “mirrors” the current state of a system, without retaining a record of previously deleted or changed items.

Backup for mobile devices

Considering how much data we now store on our mobile devices – including things we create ourselves, such as photos and videos – they should now form part of your backup plan.

Do I need to back up my phone?

Mobile apps often rely on cloud storage, so if your phone is lost or broken you can regain access to your app data by simply getting a new phone and signing in. However, you can make life easier for yourself by backing up the apps you’re using, along with your OS and application settings; these can then be quickly restored onto a new device.

Do I need iCloud storage for backup?

iCloud backup is the easiest way to back up an iPhone or iPad, as it’s built into iOS. It automatically backs up all of your personal data, photos, messages and settings to a secure cloud server. However, iCloud provides only 5GB of free storage, shared between your backups and any other items stored in your iCloud Drive. If you want to back up more data you’ll need to pay for additional storage.

Do I need backup if I have iCloud?

Simply having an iCloud account won’t protect you; you need to enable automatic backups from the Settings app on your iPhone or iPad or initiate them manually from time to time. You can also use iCloud Drive as a backup destination for a Mac or Windows PC, although you will need to manage the actual copying yourself.

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Darien Graham-Smith

Darien is one of the UK's most knowledgeable technical journalists. You will find him in PC Pro magazine, writing reviews for a variety of sites and on guitar with his band The Red Queens. His explainer articles help TechFinitive's audience understand how technology works.

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