Fabula and Syuzhet are terms originating in Russian Formalism and employed in narratology that describe narrative construction. Syuzhet is an employment of narrative and Fabula is the chronological order of the events contained in the story. They were first used in this sense by Vladimir Propp and Viktor Shklovsky.
The fabula is “the raw material of a story”, and syuzhet is “the way a story is organized”. Since Aristotle’s Poetics, narrative plots are supposed to have a beginning, middle and end. This is often achieved in film and novels via flashbacks or flashforwards. For example, the film Citizen Kane starts with the death of the main character, and then tells his life through flashbacks interspersed with a journalist’s present-time investigation of Kane’s life. The FABULA of the film is the actual story of Kane’s life the way it happened in chronological order, while the SYUZHET is the way the story is told throughout the movie, including flashbacks.