Keep an unlimited version history of all your files. Roll back your books to last year's tax records if you wish. Use our time machine feature to go back to the date you want to restore your backup as of and recover that snapshot of files & versions.
Unlike other online backup systems, we do not delete the file from your backup just because you delete the file from your computer. Other companies call this "archiving" and refuse to do it. If you delete your local file, they remove it from your online backup storage. We call it "proper backup". Over 80% of data loss occurs due to accidental deletion. With SOS you can be rest assured that we keep every version of every file forever, until you tell us to remove it.