prolog
nounUK /ˈprəʊlɒɡ/
US /ˈproʊlɔːɡ/
A prolog is a short beginning part that comes before the main story.
The prolog told us about the hero's childhood before the adventure started.
OTHER MEANINGS
2. A speech or section that introduces a play, book, or other work.
The actor stepped forward to deliver the prolog before the play began.
3. In computing, a programming language used for logic and reasoning.
She wrote a small program in Prolog to solve the puzzle.
4. An introductory event or action that leads into something bigger.
The friendly match was a prolog to the main tournament.