Apple on Tuesday (Sept. 12) unveiled its new FaceID facial recognition technology for the iPhone X—the successor to the iPhone TouchID fingerprint scanner. The company says FaceID is 20 times more secure than TouchID, and can be used for unlocking apps and using ApplePay.

Still, this kind of technology (which you can read more about here) raises a lot of questions. Here’s what we’re wondering:

Where will the data be stored?

Apple has traditionally stored biometric data on its Secure Enclave, which is like a separate encrypted computer on your phone. If the data is only held on your iPhone, it’s far safer than in the cloud.