A dramatic, non-interactive storytelling interlude (typically displayed outside the game engine), in which the IF author briefly takes control of the narrative in order to relay important developments in the plot. For instance, an IF version of Little Red Riding Hood might usefully begin with a cut-scene in which the little girl leaves her house and gets lost in the wood -- afterall, there wouldn't be much of a story if the interactor decides to stay home.
In a multimedia game, cut-scenes may involve video footage of live actors. Cartoon or computer-generated cut-scenes require the time and talents of animators, storyboard artists, voice actors, visual editors, and so forth. Multimedia is expensive to produce; for this reason, multimedia tends to be more linear than classic text-based IF.