Far from representing an exotic techology, drawn from sci-fi stories or movies, the automatic face detection imperceptibly became already part of our everyday life. In nowadays, almost any user of an average photo camera could see the automatic drawing of a colored rectangle which is framing the faces of human subjects towards which the respective camera objective is pointed to. Few of them asked themselves however how is this possible, and probably fewer know more or less the answer to this question. The present paper aims to present the problematics of automatic face detection, with a brief overview of the specific difficulties, and of the main types of approaches in solving this problem, while detailing - at a level which aims to be as accessible as possible - of one of the most well known and used method, the Viola-Jones one. This paper don’t intend to be an exhaustive survey or a monography on the domain, but only an introduction to this one, easily understandable by most people, while also trying to highlight the beauty and elegance of the innovation, the efficiency and performances brought by the Viola-Jones method.