Film is an important art form; films entertain, educate, enlighten, and inspire audiences. The visual elements of cinema need no translation, giving the motion picture a universal power of communication. Films are also artifacts created by specific cultures, which reflect those cultures, and in turn, affect them.
Traditional 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 a combination of physiological and psychological effects. One is 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 also perceive motion due to psychological effects called beta movement and the phi phenomenon.
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; photo-play; flick; and most commonly, movie. Additional terms for the field in general include the big screen; the silver screen; the cinema; and the movies.