With the release of a third Harry Potter film, do you know your Hedwigs from your Hogwarts, the Malfoys from the Weasleys and a Hufflepuff from a Slytherin?
Here is BBC News Online's essential guide to bluffing your way around the magical world of author JK Rowling.
Harry Potter is an orphan who has to live with his horrible aunt and uncle - Vernon and Petunia Dursley - since his parents were killed when he was barely one year old.
At the age of 11, he discovers he has special wizard skills. He goes off to wizard school where he gets caught up in murderous mysteries.
Daniel Radcliffe plays the boy wizard in the Harry Potter films
Harry has green eyes, untidy black hair and a lightning-shaped scar on his forehead.
He has a fat, spoiled cousin called Dudley.
They all live at 4 Privet Drive, which Petunia keeps in immaculate condition. Harry, however, is made to sleep in a room under the stairs.
Harry's parents were James and Lily. James came from a family of sorcerers but Lily was descended from mere mortals.
Once a year, Harry escapes from the dire Dursleys when he goes off to school, returning only for the summer holidays.
He takes the train from platform nine and three-quarters at King's Cross station in London to a magical world, where he joins his classmates at Hogwarts School of Witchcraft and Wizardry.
Hogwarts is a co-educational, non-fee-paying boarding school for pupils aged 11 to 17. It is housed in a big castle next to a lake and forest and is run by Albus Dumbledore and his deputy Minerva McGonagall.
The most eminent teacher is the sinister Professor Snape. The most endearing staff member is Hagrid, a kindly giant who drinks too much and likes dragons.
Michael Gambon plays Dumbledore in the latest Harry Potter film
The school uniform consists of robes, cloaks and pointed hats. Pupils are also allowed a "familiar" such as a rat or toad. (Harry's creature is an owl called Hedwig.)
Hogwarts is divided into houses, rather like a public school. They include Slytherin, Ravenclaw, Hufflepuff and Gryffindor - each with its own ghost.
Pupils are divided up between the houses - by the talking Sorting Hat - depending on their character.
Pleasant, easy-going types go into Hufflepuff. Those with a more than average inclination for study go to Ravenclaw. Bright and pleasant pupils, like Harry, go to Gryffindor.
Harry makes some very good friends at Hogwarts. But his closest pals are Hermione Granger and Ron Weasley, who accompany him on many dangerous and thrilling journeys.
Hermione is hardworking, angst-ridden and swotty but also kind and courageous. She has bushy brown hair, large front teeth and memorises the course books by heart.
Harry's best friends at Hogwarts are Ron (left) and Hermione
Ron is not too good at magic but is loyal, brave and great company. He comes from a poor but loving family of seven.
Together, the three children undergo a tough regime including classes in Herbology, Charms, Magic Potions and Defence Against the Dark Arts.
Harry of course is a brilliant pupil, excelling at magic. He is also a deft player of the school's traditional game, Quidditch.
The Quidditch season starts in November and sees teams of seven competing on broomsticks, divided up into Chasers, Beaters, Keepers, Seekers and Bludgers. The Quaffle is the ball and a Golden Snitch earns a team extra points.
Dark wizard Voldemort. He is the scariest character in the Potter saga, driven by his lust for power into a life of evil.
He killed Harry's parents and is determined to finish off their son too. (The scar on Harry's forehead is the result of one failed murder attempt.)
Harry's enemy at school is Draco Malfoy.
Harry Potter's biggest rival at Hogwarts is Draco Malfoy
The Dementors are prison guards who track people by sensing their emotions. They disable their victims by sucking out all positive thoughts and with a kiss can take a soul - leaving the body alive but emotionless.
Aunt Marge, another of Harry's unpleasant relatives, is rather overweight and keeps bulldogs.
An important point of reference is the term Muggle - Potter language for a normal mortal, as opposed to someone with magic powers.
There is a Muggle Protection Act that prevents people of the magical community from using magic in a way that Muggles can see or come in contact with.
Each book charts a year's progress through Hogwarts School for Harry and his friends.
We were introduced to them in Harry Potter and the Philosopher's Stone (Sorcerer's Stone in the US) in 1997.
Harry Potter and the Chamber of Secrets followed in 1998 and charted Harry, Hermione and Ron's second year at Hogwarts. This time around, though, the mood is darker as evil voices and messages point Harry towards an unsolved mystery.
Harry Potter and the Prisoner of Azkaban emerged in 1999. It tells the story of Sirius Black, who escapes from the high security wizard prison of Azkaban and then tries to kill 13-year-old Harry.
At 640 pages, 2000's Harry Potter and the Goblet of Fire was double the size of the previous instalment.
JK Rowling has written five Harry Potter books to date
The story involved a Triwizard Tournament that saw Hogwarts face two other schools of wizardry, Durmstrang and Beauxbatons.
2003 saw the eagerly-awaited publication of Rowling's fifth book, Harry Potter and the Order of the Phoenix, which clocked in at a whopping 740 pages.
Phoenix - which became the fastest-selling book of all time - saw Harry face expulsion from Hogwarts and the destruction of his wand.
No release date has been set for the sixth or seventh books, the last two instalments in JK Rowling's epic saga.
Author JK Rowling - her surname is pronounced "Rolling" - took the name Potter from a family who lived four doors down from her when she was a young girl in Winterbourne, south Gloucestershire.
The swotty Hermione is based on Rowling herself as a schoolgirl.
Ron is based on her oldest friend, Sean.
Joanne Kathleen Rowling is the world's best-paid author
Harry is partly imaginary but Rowling says there is a lot of herself in him, while Aunt Marge was based on her maternal grandmother, Frieda.
Then there are the Dementors. Introduced in Harry Potter and the Prisoner of Azkaban, these evil creatures are drawn from Rowling's own experience of suffering from depression.