Harry Potter is a series of seven fantasy novels written by the British author J. K. Rowling. The books chronicle the adventures of the adolescent wizard Harry Potter and his best friends Ron Weasley and Hermione Granger, all of whom are students at Hogwarts School of Witchcraft and Wizardry. The main story arc concerns Harry's quest to overcome the evil dark wizard Lord Voldemort, whose aim is to subjugate non-magical people, conquer the wizarding world, and destroy all those who stand in his way, especially Harry Potter.

Since the 30 June 1997 release of the first novel Harry Potter and the Philosopher's Stone, the books have gained immense popularity, critical acclaim and commercial success worldwide. The series has also had some share of criticism, including concern for the increasingly dark tone. As of June 2011, the book series has sold about 450 million copies and has been translated into 67 languages, and the last four books consecutively set records as the fastest-selling books in history.

A series of many genres, including fantasy and coming of age (with elements of mystery, thriller, and romance), it has many cultural meanings and references. According to Rowling, the main theme is death,although it is primarily considered to be a work of children's literature. There are also many other themes in the series, such as love and prejudice.
English-language versions of the books are published by Bloomsbury in the United Kingdom, Scholastic Press in the United States, Allen & Unwin in Australia, and Raincoast Books in Canada. In October 2011, the series will be released in various ebook formats through "Pottermore." The books have been made into an eight-part film series by Warner Bros. Pictures, with the seventh book split into two parts; it is the highest grossing film series of all time. The series also originated much tie-in merchandise, making the Harry Potter brand worth in excess of $15 billion.

The novels revolve around Harry Potter, an orphan who discovers at the age of eleven that he is a wizard, living within the ordinary world of non-magical, or Muggle, people. His ability is inborn and such children are invited to attend a school that teaches the necessary skills to succeed in the wizarding world.Harry becomes a student at Hogwarts School of Witchcraft and Wizardry and it is in here where most of the novels' events take place. As Harry develops through his adolescence, he learns to overcome the problems that face him: magical, social and emotional, including ordinary teenage challenges such as friendships and exams, and the greater test of preparing himself for the confrontation that lies ahead.

Each book chronicles one year in Harry's life with the main narrative being set in the years 1991–98. The books also contain many flashbacks, which are usually described by characters viewing memories in a device called a Pensieve.
When the story of Harry Potter opens, it is clear that some remarkable event has taken place in the wizarding world, an event so very remarkable that even the Muggles notice signs of it. The full background to the stories and to the person of Harry Potter is only revealed gradually, through the series. In the first book Harry discovers that as a baby he witnessed his parents' murder by the power-obsessed dark wizard, Lord Voldemort, who then attempted to kill him also

Harry Potter and the Deathly Hallows Trailer Official HD
For reasons not immediately revealed, the spell with which Voldemort tried to kill Harry rebounded. Harry survives with only a lightning-shaped scar on his forehead as a memento of the attack, and Voldemort disappears. As its inadvertent saviour from Voldemort's reign of terror, Harry becomes a living legend in the wizarding world. However, at the orders of the venerable and well-known wizard Albus Dumbledore, the orphaned Harry is placed in the home of his unpleasant Muggle (non-wizard) relatives, The Dursleys. The Dursleys keep him safe but hide his true heritage from him in hopes that he will grow up "normally".
The first novel in the series, Harry Potter and the Philosopher's Stone (changed in some countries to Harry Potter and the Sorcerer's Stone), begins near Harry's eleventh birthday. Half-giant Rubeus Hagrid reveals Harry's history and introduces him to the wizarding world.The environment J. K. Rowling created is completely separate from reality yet intimately connected to it. While the fantasy land of Narnia is an alternative universe and the Lord of the Rings’ Middle-earth a mythic past, the wizarding world of Harry Potter exists in parallel within the real world and this is how Potter's world contains magical elements similar to things in everyday life. Many of its institutions and locations are recognizable, such as London.It comprises a fragmented collection of hidden streets, overlooked and ancient pubs, lonely country manors and secluded castles that remain invisible to the Muggle population.
With Hagrid's help, Harry prepares for and undertakes his first year of study at Hogwarts. As Harry begins to explore the magical world, the reader is introduced to many of the primary locations used throughout the series. Harry meets most of the main characters and gains his two closest friends: Ron Weasley, a fun-loving member of an ancient, large, happy, but hard-up wizarding family, and Hermione Granger, a gifted and hard working witch of non-magical parentage.Harry also encounters the school's potions master, Severus Snape, who displays a deep and abiding dislike for him. The plot concludes with Harry's second confrontation with Lord Voldemort, who in his quest for immortality, yearns to gain the power of the Philosopher's Stone.
The series continues with Harry Potter and the Chamber of Secrets describing Harry's second year at Hogwarts. He and his friends investigate a 50-year-old mystery that appears tied to recent sinister events at the school. Ron's younger sister, Ginny Weasley, enrols in her first year at Hogwarts, and finds a notebook which turns out to be Voldemort's diary from his school days. Ginny becomes possessed by Voldemort through the diary and opens the "Chamber of Secrets", unleashing an ancient monster which begins attacking students at Hogwarts. The novel delves into the history of Hogwarts and a legend revolving around the Chamber. For the first time, Harry realises that racial prejudice exists in the wizarding world, and he learns that Voldemort's reign of terror was often directed at wizards who were descended from Muggles. Harry also learns that his ability to speak Parseltongue, the language of snakes, is rare and often associated with the Dark Arts. The novel ends after Harry saves Ginny's life by by destroying a basilisk and the diary, in which Voldemort saved a piece of his soul (although Harry does not realise this until later in the series). The concept of storing part of one's soul inside of an object in order to prevent death is officially introduced in the sixth novel under the term "horcrux".
The third novel, Harry Potter and the Prisoner of Azkaban, follows Harry in his third year of magical education. It is the only book in the series which does not feature Voldemort. Instead, Harry must deal with the knowledge that he has been targeted by Sirius Black, an escaped murderer believed to have assisted in the deaths of Harry's parents. As Harry struggles with his reaction to the dementors—dark creatures with the power to devour a human soul—which are ostensibly protecting the school, he reaches out to Remus Lupin, a Defence Against the Dark Arts teacher who is eventually revealed to be a werewolf. Lupin teaches Harry defensive measures which are well above the level of magic generally shown by people his age. Harry learns that both Lupin and Black were close friends of his father and that Black was framed by their fourth friend, Peter Pettigrew.In this book, another recurring theme throughout the series is emphasised—in every book there is a new Defence Against the Dark Arts teacher, none of whom lasts more than one school year.