Short answers, pulled from the story.
Backstory is the fictional history of a character before the main plot events. It serves as the set of events that establishes a character's past or leads directly up to the main plot. This hidden history provides the weight necessary for actions in the present moment to feel real to a reader or viewer.
Recollection allows a character to call something to mind and bring forth information from before the beginning of the story. A character's memory enables fiction-writers to retrieve details from earlier in the timeline or from the distant past to inform the current narrative. This process bridges the gap between the present action and the past events.
Actors create their own backstories to fully inhabit their roles and interpret the script. This process involves constructing a fictional history of a character before the main plot events that a performer creates during their preparation for the role. By inventing events that never appear on screen or page, performers generate subtle emotional cues and behavioral patterns that make a character feel three-dimensional.
Retroactive continuity is the adjustment device known as retcon used when a later creation of a backstory conflicts with a previously written main story. This phenomenon occurs when a new story or character history contradicts established facts, forcing writers to rewrite or adjust the past to maintain consistency. The concept of a shared universe allows for multiple creators to contribute to a single narrative world but introduces the risk of conflicting histories that must be resolved.
Backstory may be revealed by various means including flashbacks, dialogue, direct narration, summary, recollection, and exposition. Flashbacks allow the audience to witness past events directly, while dialogue can reveal history through conversation between characters. Direct narration provides a straightforward account of past events, while summary condenses the history into a brief overview.