The script identifies the coordinates of the finish line or the final badge giver and teleports your character there instantly.
These scripts often ruin the experience for others in multiplayer races and can cause game servers to crash if not written correctly. Alternative: Learning to Build and Script Very Easy Parkour Obby Instant Finish Script
Some scripts simulate touching every checkpoint in sequence within seconds, which triggers the game's "win" state. The script identifies the coordinates of the finish