How do facial recognition systems actually recognize faces?

Question

Neural networks

What human biometric data do they scan? After all, people change. How do they manage to recognize a person from different angles, even if two pictures look very different by eye?

Answer 1

The face is localized, the resulting image is normalized, then some set of features is considered from it, the objects most similar to this are searched throughout the database, in the simplest case, the closest of them is taken as an answer.