The golden rule of backups is refreshingly simple: keep more than one copy of the things you care about, and store those copies in more than one place. Operating systems and apps can always be reinstalled, but your photos, home videos, and personal documents cannot be recreated. Those irreplaceable files should be your top priority, along with anything that took hours to build, like a carefully ripped music collection.
An external drive is the easiest place to start. Windows File History and Mac Time Machine will copy your files automatically and quickly, and restoring is fast. The catch is that a drive sitting next to your laptop can disappear in the same fire, flood, or burglary. That's why it helps to add an offsite copy, such as an online backup service that runs quietly in the background, or simply a drive kept at a relative's house.
Sync is not the same as backup
Services like Dropbox, Google Drive, and OneDrive are wonderful for keeping files in step across devices, but they are designed to mirror changes, including accidental deletions. Dedicated backup services keep older versions so you can roll back, though many purge deleted files after a set period, so check the retention rules. A home network storage box is another option that can back up every computer in the house at once.
Whatever mix you choose, automate it. Backups you have to remember to run tend not to happen. A comfortable setup for many families is a local drive plus an online service, or a free sync folder plus an occasional external-drive copy. Then picture your computer dying tomorrow and ask yourself: what would I lose? If the answer is nothing important, you're in good shape.
Source: How-To Geek
