What is Backup?
A saved copy of your data kept somewhere safe, so you don't lose it to theft, damage, or ransomware.
A good backup is automatic (so you never forget), regular, and stored separately from the original — in the cloud or on a drive you disconnect. Test it occasionally by restoring a file. Phones make this easy with built-in cloud backup; turn it on and your photos and messages survive loss, theft, and breakage.