A flashback is an interjected scene that takes the narrative back in time from the current point in the story.
THE VIRGINS - FLASHBACKS, MEMORIES, AND DREAMS (OFFICIAL ... by CultRecordsNYC
Flashbacks are often used to recount events that happened before the story's primary sequence of events to fill in crucial backstory.
A backstory, background story, back-story, or background is a set of events invented for a plot, presented as preceding and leading up to that plot.
Flashbacks by Mikey Bolts
In the opposite direction, a flashforward reveals events that will occur in the future.
A flashforward is a scene that temporarily takes the narrative forward in time from the current point of the story in literature, film, television and other media.
Both flashback and flashforward are used to cohere a story, develop a character, or add structure to the narrative.
In literature, internal analepsis is a flashback to an earlier point in the narrative; external analepsis is a flashback to a time before the narrative started.
In movies and television, several camera techniques and special effects have evolved to alert the viewer that the action shown is a flashback or flashforward; for example, the edges of the picture may be deliberately blurred, photography may be jarring or choppy, or unusual coloration or sepia tone, or monochrome when most of the story is in full color, may be used.
Monochrome describes paintings, drawings, design, or photographs in one color or values of one color.