Backup (the 3-2-1 rule)
What is Backup (the 3-2-1 rule)?
A copy of your files stored somewhere else, so a dead computer doesn't mean dead data. The 3-2-1 rule: keep 3 copies of your data, on 2 different types of media, with 1 copy stored off-site — so a single fire, flood, or ransomware attack can't destroy everything.
Why Backup (the 3-2-1 rule) Matters
Backups only matter the day you need them. If your 'backup' is an external drive plugged into the same computer, ransomware or a power surge can take out both at once. Verify your backups actually restore — don't wait for a crisis.
Related Topics
Related Terms
Ransomware
Malware that encrypts your files and demands payment for the decryption key. It spreads through phishing emails, malicious downloads, or compromised remote access. Paying doesn't guarantee you'll get your files back — and marks you as a target for repeat attacks.
SecurityCloud
Someone else's computers, rented. Your files and apps live on their servers and reach you over the internet.
CloudEncryption
Scrambling data so only someone with the right key can read it — even if it's stolen.
Security