how does harry come back to life

Harry Potter comes back to life after being hit by Voldemort's Killing Curse for a second time because he is uniquely protected by several magical factors tied to his identity and choices. Voldemort had unintentionally made Harry a Horcrux by embedding a piece of his soul in Harry, which means that when Voldemort hit Harry with the curse, it destroyed the Horcrux part, not Harry's actual soul. Furthermore, Voldemort used Harry's blood to recreate his own body, which tethered Harry's life protection to Voldemort's. This protection, combined with Harry's possession of all three Deathly Hallows (making him the "Master of Death"), gave him the mystical choice to either move on to the afterlife or return to the living world. When Harry meets Dumbledore in a limbo-like state, he chooses to come back to life and ultimately defeats Voldemort.