What is a computer backup and how to backup files

What is a backup

Backup is a copy of data stored separately from the original files. Regular backups stored in secure or multiple locations are essential.

When to backup

Official corporate IT industry guides suggest creating a regular backup schedule to prevent data loss and protect data. The frequency of backups should be determined based on factors such as the amount of data being backed up, the importance of the data, and the speed and capacity of the backup medium.

For example, the National Institute of Standards and Technology (NIST) recommends that organizations establish a backup schedule based on the following criteria:

  • The frequency of data change and the rate of data growth
  • The importance and sensitivity of the data
  • The criticality of the system or application
  • The type and size of the storage media being used for backup
OrganizationRecommended Backup Frequency
NISTWeekly for critical data or more frequently if necessary.
MicrosoftDaily for important data and applications.
GoogleEvery 15 minutes or hour for critical data, daily or weekly for the other.

Where to backup

You can store backup data on external USB or network drives, or cloud storage services. You also can backup to an internal drive, which is faster, but if the computer fails, the internal drive may also fail, leading to potential data loss.

Cloud vs USB drives

Cloud storage is convenient and can be accessed from anywhere, but uploading data to cloud storage can be over 40 times slower than copying data to a USB drive. Additionally, cloud storage may be less secure than local storage because data is stored on servers that are maintained by a third party.

USB drives, on the other hand, are less vulnerable to internet-based threats such as hacking or data breaches, which makes them a more secure option for storing sensitive information.

How to backup

Most Windows and Mac devices have a built-in backup feature, but some users may prefer to use third-party software for convenience. Third-party backup solutions like Acronis may offer features like cloning, which is not typically available in built-in backup tools.

Built-In Backup


By default, Windows offers the option to sign in to a Microsoft account and backup data to OneDrive. However, this may not always be feasible due to slow upload speeds. For example, uploading 10GB of data to OneDrive over an average NBN can take 30 min. Alternatively, copying 10GB of data to a USB 3.0 drive with a transfer rate of 100 MB/s can take approximately 1.5-2 minutes.

If you're looking to upload 1 terabyte of data, it would take approximately 55 hours to upload to OneDrive using an average NBN connection of 50 Mbps. In addition to the time it takes to upload the data, cloud storage also comes with a monthly fee. For instance, Microsoft offers 1TB of storage for $13.00 AUD per month, which includes a license for Microsoft Office 365.

In comparison, copying 1 terabyte of data to a USB 3.0 drive with a transfer rate of 100 MB/s can take approximately 2-3 hours and cost $80 for a 1Tb USB drive.

Fortunately, you can easily store backups on a USB or network drive by following a few simple steps.

File History can automatically back up personal files like documents, photos, and music to an external drive or network location. To turn on File History, go to Control Panel > All Control Panel Items > File History. To change the backup frequency, go to Control Panel > All Control Panel Items > File History > Advanced Settings.

To recover files from File History, follow these steps:

  • Go to the folder where the lost or damaged file was stored.
  • Right-click on the folder and select Properties from the context menu.
  • In the Properties window, click on the Previous Versions tab.
  • Browse through the previous versions of the file until you find the one you want to restore.
  • Click the Restore button to restore the file to its original location or choose a new location for the restored file.

In addition to File History, Windows Backup allows you to create a system image, back up individual files and folders, and create a backup schedule. To backup to a USB or network drive in Windows 11, select a backup location by going to Control Panel > All Control Panel Items > Backup and Restore (Windows 7).


  • Time Machine: This feature automatically backs up the entire system and personal files to an external drive, network location, or Time Capsule. Time Machine is available on macOS X 10.5 and later versions.


  • iCloud Backup: This feature automatically backs up your iPhone data, including photos, contacts, and settings, to iCloud over Wi-Fi. iCloud Backup is available on iPhones running iOS 5 or later versions.
  • iTunes Backup: This feature creates a backup of your iPhone data, including photos, contacts, and settings, to your computer using iTunes. iTunes Backup is available on iPhones running iOS 4 or earlier versions.

What to backup

You can back up a few selected files or folders or make an exact copy of an entire hard disk drive. A typical selection of files for backup includes folders (default for Windows Backup): My Documents, My Pictures, My Music, My Videos, and Downloads. To backup Outlook 2010 emails and addresses, the Outlook Files folder with .pst file must be selected.

Backing Up vs Copying Data

Backing up data is not the same as copying data. Copying creates an exact duplicate of the data that is ready to use immediately. Backup software, however, usually compresses data and stores it in an archive that can only be retrieved using the same software. For example, Microsoft Backup and Restore must be used to retrieve data from the Windows Backup archive. The same applies to Apple Mac Time Machine. If a copy of data is desired, a script can be written using free built-in system commands, such as robocopy.

Cloning vs copying

Cloning an entire hard disk drive involves making an exact copy of the drive, which can be done to an image file or another hard drive. Cloning is faster than copying individual files and allows you to restore the system almost immediately with all the settings and programs intact. In contrast, backing up files requires the operating system and programs to be reinstalled, making cloning more time and cost-effective for disaster recovery. Popular cloning software includes Norton Ghost and Acronis True Image.

Microsoft Backup and Apple Mac's Time Machine can also backup the system, but not as an image. Instead, they back up data files and program and system settings. They require the operating system to be reinstalled before recovery, which is longer than restoring from a cloned image. Systems recovered from such backups are not the same as the originals.

Coping vs cloning
Files copyingDisk cloning
Need to know what to backupYesNo
Ready to run system immediately after failureNoYes
Need a backup softwareNot necessaryYes
Time needed for recoveryMoreLess
Space neededLessMore
Cloud backupYesNo