Question: how elder wand belongs to harry?
Answer: Draco had disarmed Dumbledore before Snape killed him. ... He believed he was now the Elder Wand's true master, but in the Battle of Hogwarts, Harry Potter, his young adversary, revealed to Voldemort that the wand had not belonged to Snape, but to Draco, and, after defeating Draco himself, Harry Potter.