Online Backup & Online Storage Aren’t the same:
- Online Backup: designed to permanently save of data, for occasional access (for restore) purpose, e.g. CrashPlan, Carbonite, etc.
- Online Storage: designed to facilitate regular access, via web, mobile apps, and desktop app that quite often integrated into your operating system; e.g. Dropbox, SkyDrive, Google Drive, SugerSync etc.
A must-read for choosing online backup: http://www.makeuseof.com/tag/read-choosing-online-backup-provider/