Comment by pcl

In the industry, that’s known as face (or facial) detection, which is a different problem than face recognition.

Face recognition means computing which individual from some other database of people a particular face belongs to.

There’s also face tracking — detecting a face in an image and then tracking the same face across subsequent images. Which is often implemented by using a face recognition approach, but without any predefined catalog of people — you just dynamically fill up your face database as faces appear in the image sequence / video source.