With Practice Master Pro you are not dependant on an internet connection. You have all your data with you all the time whether online or offline. You can receive updates from the other practitioners when you are in the practice, and via the cloud when you are off-site. And if you are completely without internet you still have all your data with you. And with powerful security permissions and encryption your data is always safe from prying eyes.
Of course the synchronisation features are entirely optional, you can always use the client/server mode if you do not want any of your data to ever leave your practice.