Face ID is completely different.
FaceID is a locked system that has only one purpose... to unlock your iPhone. The same technology could be used to accurately identify you for reason including unlocking your car, house, your safe or even your top secret lab. FaceID is used as a key.
It is using the laser distance lens (Lidar) to create a 3D representation of your face... then converting the aligned 3D data into a hash value and comparing it to what is stored in the secure vault. At no time is your face ever sent to Apple servers... everything is run locally on the device.
This is similar to how passwords are stored now. You input the password and it is sent to the server which runs it though a hash and compares it to the hash stored in the database. It is possible, to reverse engineer your password by running a lot of possible passwords through the server and seeing if they are a match. It is even possible for 2 passwords to have the identical hash but the likelihood is very small. The stronger the hashing algorithm used, this becomes even less likely.
Facial Recognition operates on some of the same principles but it is working off of flat 2D image data as its source, not 3D data like the iPhone. There is a lot of guess work involved for the AI, and it can never be as accurate as a 3D scan. For example, Facebook for a while mixed up photos of my wife and daughter thinking they were the same person.
Facial Recognition can be used for any image source including CCTV cameras, photos uploaded to any internet website (including social media), video, even possibly infrared cameras if the AI was trained for them. The same AI could be tasked to identify voice prints as well. Or it could be trained to recognize other things in photos like illegal drugs, guns, etc and notify the police as soon as it does.