Multi-image is the now largely obsolete practice and business of using 35mm slides (diapositives) projected by single or multiple slide projectors onto one or more screens in synchronization with an audio voice-over or music track. Multi-image productions are also known as multi-image slide presentations, slide shows and diaporamas and are a specific form of multimedia or audio-visual production. The term multi-image is sometimes used to describe digital photo image computer programs that combine or change images on-screen, for photo montages, and image stitching.