用英语来介绍一下关于电影的常识

Film encompasses individual motion pictures, the field of film as an art form, and the motion picture industry. Films (also referred to as movies or motion pictures) are produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects.

Films are cultural artifacts created by specific cultures, which reflect those cultures, and, in turn, affect them. Film is considered to be an important art form, a source of popular entertainment and a powerful method for educating — or indoctrinating — citizens. The visual elements of cinema give motion pictures a universal power of communication. Some films have become popular worldwide attractions by using dubbing or subtitles that translate the dialogue.

Films are made up of a series of individual images called frames. When these images are shown rapidly in succession, a viewer has the illusion that motion is occurring. The viewer cannot see the flickering between frames due to an effect known as persistence of vision, whereby the eye retains a visual image for a fraction of a second after the source has been removed. Viewers perceive motion due to a psychological effect called beta movement.

The origin of the name "film" comes from the fact that photographic film (also called film stock) has historically been the primary medium for recording and displaying motion pictures. Many other terms exist for an individual motion picture, including picture, picture show, moving picture, photo-play and flick. A common name for film in the United States is movie, while in Europe the term cinema is preferred. Additional terms for the field in general include the big screen, the silver screen, the cinema and the movies.