This document provides an overview of facial recognition systems. It discusses what facial recognition is, which is a computer system that identifies people by analyzing facial features from images and video. It explains that facial recognition started in the 1960s and is now commonly used for security applications. The document outlines different approaches to facial recognition, including two-dimensional and three-dimensional systems, and describes some of the techniques involved like feature extraction and classification. It also provides details about a specific facial recognition product called FA007 and its uses for access control.