The story opens with the unrestrained celebration of a normally secretive wizarding world which for many years had been terrorised by Lord Voldemort. The previous night, Voldemort had discovered the refuge of the hidden Potter family, and killed Lily and James Potter. However, when he attempted to kill Harry, the Avada Kedavra killing curse rebounded upon him, and Voldemort was destroyed, becoming nothing more than a spirit: neither dead nor alive. Harry, meanwhile, was left with a distinctive lightning bolt-shaped scar on his forehead, the only physical sign of Voldemort's curse. Harry is the only known survivor of the killing curse, and his mysterious defeat of Voldemort results in him being dubbed "The Boy Who Lived" by the wizarding community. The following night, a wizard (Hagrid) delivers Harry to what will be his residence for many years afterward. The orphaned Harry is subsequently raised by his cruel, non-magical relatives, the Dursleys, who, in an attempt to rid him of his magical powers, hide his magical heritage and give him severe punishments after any strange occurrences. However, as his eleventh birthday approaches, Harry has his first contact with the magical world when he receives letters from Hogwarts School of Witchcraft and Wizardry, which are delivered by owls. The letters are taken from him by his Uncle before he has a chance to read them. On his eleventh birthday he is informed by Hagrid, the gamekeeper of Hogwarts, that he is in fact a wizard and has been invited to attend the school. Each book chronicles one year in Harry's life, which is mostly spent at Hogwarts, where he learns to use magic and brew potions. Harry also learns to overcome many magical, social, and emotional obstacles as he struggles through his adolescence, Voldemort's rise to power, and the Ministry of Magic's constant denials of Voldemort's return.
The wizarding world in which Harry finds himself is both utterly separate from and yet intimately connected to our own world. While the fantasy world of Narnia is an alternative universe and the Lord of the Rings’ Middle-earth a mythic past, the wizarding world of Harry Potter exists alongside ours and contains magical elements analogous to things in the non-magical world. Many of its institutions and locations are in towns and cities, including London for example, that are recognisable in the primary world. It possesses a fragmented collection of hidden streets, overlooked and ancient pubs, lonely country manors and secluded castles that remain invisible to the non-magical population (known as "Muggles" e.g.: The Dursleys). Wizard ability is inborn, rather than learned, although one must attend schools such as Hogwarts in order to master and control it. However it is possible for wizard parents to have children who are born with little or no magical ability at all (known as "Squibs" e.g.: Mrs. Figg, Argus Filch). Since one is either born a wizard or not, most wizards are unfamiliar with the Muggle world, which appears stranger to them than their world does to us. The magical world and its many fantastic elements are depicted in a matter-of-fact way. This juxtaposition of the magical and the mundane is one of the principal themes in the novels; the characters in the stories live normal lives with normal problems, for all their magical surroundings.
