In Harry Potter and the Deathly Hallows – Part 2, Harry uses Reparo to repair his broken wand.
Harry's holly-and-phoenix-feather wand is damaged during the confrontation with Voldemort in the Forbidden Forest. After the Battle of Hogwarts, Harry uses the Elder Wand to mend it. He then returns the Elder Wand to Dumbledore's tomb, intending for its power to end with him, while keeping his own restored wand.
Reparo is a repairing charm used elsewhere in the films to fix damaged objects. It is distinct from Expelliarmus, the disarming spell Harry frequently uses, and Lumos, the wand-lighting charm. These spells are often confused because all are among the series' most recognizable spoken incantations.
The wand-repair scene is important because it visually restores Harry's original magical identity. It also connects the film's ending to the larger theme of choosing personal loyalty over the destructive power associated with the Deathly Hallows.