With SpiderOak ONE you only sync the files or folders that you choose, and you do not have to sync everything you back up. This is different from other well known services. With many of them, selective sync is opt-out: everything is synced by default but you may be able to opt out of synchronizing certain folders. With SpiderOak ONE, it is opt-in: you begin by backing up only and not syncing anything, and then you can choose individual folders that you want to sync. You may set up an unlimited number of syncs, and each sync can be between any combination of your devices. Making it opt-in gives you better default privacy and security.