Analysis of the documentary phenomenon from different areas: its social relevance, the borders and boundaries with fiction cinema, the tools and possibilities of animation in documentary, the contributions of journalism to the genre, the taxonomy and rhetoric of the documentary, as well as the Mexican context, the possibilities and limits of financing and its current boom in film production. Professor Carlos Mendoza is undoubtedly one of the filmmakers most qualified for these digressions, not only for his almost three decades as a teacher and his extensive production, but also for dealing with the importance of documentary in the academic and cultural field, as evidenced by his efforts in the recent foundation of the Master's Degree in Documentary Film at UNAM.