3-2-1 backup
A 3-2-1 backup means three copies of your data, on two different kinds of storage, with one copy kept offline or offsite.
The rule protects against most kinds of loss: a dead drive, a stolen laptop, a fire, or ransomware that encrypts everything connected.
Synced folders are not enough on their own, because they copy deletions and encrypted files too. Choose a backup that keeps old versions.
Some people extend it to 3-2-1-1-0: one copy offline or unchangeable, and zero errors when you test a restore.
Learn it in a 6-minute lessonBackups: the 3-2-1 rulethe undo button for ransomware