Film is a thin, flexible material coated with chemicals that react to light, used in cameras to capture photographs and movies. Before digital cameras existed, photographers loaded film into their cameras, and when they pressed the shutter button, light hit the film and created an image. The film had to be developed in a darkroom using special chemicals before anyone could see the pictures.

The word also means a movie or motion picture. When we say we're going to see a film, we mean we're watching a story told through moving images on a screen. Directors like Steven Spielberg make films that millions of people watch in theaters. Film can refer to serious artistic movies (Casablanca is considered a classic film) or to any movie at all.

Film works by taking many individual photographs very quickly, usually 24 pictures per second. When these images play back rapidly, our brains see them as continuous motion rather than separate pictures. This trick of perception makes filmed stories feel alive and real.

You might also encounter the word describing a thin layer covering something, like a film of ice on a puddle in winter or a film of dust on an old book. In each case, film suggests something thin that covers or captures something else.