Backup means keeping copies of your files in case the originals are lost or damaged, for example by software problems, malware, disk failure, fire, theft, or human error.

To be most effective, backups should happen frequently and automatically. Some backup systems also retain versions of files you edit, and even files you delete—a kind of long-term ‘undo’ facility.

Local backup

With local backup the copies are stored on a hard drive or flash drive (memory stick). There’s a one-off cost to buy this, typically not more than £50.

You also need backup software. For Mac users I recommend the built-in Time Machine, while my preference on Windows is Acronis True Image.

Note: Although Windows 7 included a good local backup facility, my experience of the Windows 10 equivalent, File History, has consistently been that it is not reliable. I no longer recommend it to anyone.

Online backup

With online backup the copies are stored by an IT company of your choice. They might call it ‘the cloud’; in reality, this means large warehouses filled with computers with very high-capacity disks.

For a basic service, I recommend iCloud on Mac or OneDrive on Windows. Google Drive and Dropbox are also good and work on both platforms. All four start out free, but a small monthly payment buys more capacity—if you’ve got lots of photos, for example.

More comprehensive options I recommend include Acronis True Image and Backblaze.

Belt and braces

I advise people to combine both local and online backup because they mitigate different risks. For example: