Film is a photographic sheet of plastic, coated with an emulsion of light-sensitive silver halide salts, used for taking still pictures. When photographic film is exposed to a form of electromagnetic radiation (be it light or X-rays), an invisible image forms onto it. The image can become visible under certain chemical processes, known as film developing.
Film stock is defined as a photographic film used for motion picture capture. In TV production, a similar term is video tape.
A film, movie or motion picture is a series of moving images that are recorded with cameras or are computer generated using animation and special effects techniques. A film is constructed out of a series of still frames that create the illusion of motion when played in rapid succession. Filmmaking is considered to be a form of art, a source of entertainment, as well as a tool for educating or indoctrinating individuals.
You’ll find bloggers talking about film at sites like film.dc.gov.