Ronald Weasley - Red-haird boy wizard from a large, poor wizarding family that lives in "The Burrow". Ron also attends Hogwarts and is best friend to Harry and Hermione.

Hermione Granger - A brainy girl wizard whose parents are both muggle dentists. She also attends Hogwarts and is best friends with Harry and Ron. Hermione has a pet cat named Crookshanks. In the books, Hermione is romantically linked to Viktor Krum and Ron Weasley.

Albus Dumbledore - Headmaster of Hogwarts School for Witchcraft and Wizardry. He is known as a very old and wise wizard who regards Harry very warmly. Dumbledore is a key figure in the battle against Lord Voldermort and is often at odds with the Ministry of Magic.

Lord Voldemort - Dark Wizard who leads an army of other dark wizards called the "Death Eaters". Originally named "Tom Riddle", and schooled at Hogwarts in his youth, Voldemort grew into a murderous prophet responsible for the killing of many muggles and witches - including the parents of Harry Potter.

Dementor - a dark, ethereal magical being that is capable of sucking the soul out of a person's body. People in their presence lose all thoughts of happiness and feel chilled. Humans are unable to see them. Dementors serve as prison guards at the famous wizard's prison, Azkaban.

Golden Snitch - a rapidly moving golden ball used in Quidditch games. The very valuable winged ball is released at the start of the game and must be caught by a team's "Seeker" in order to end the game.

Marauder's Map - A magical map that displays the layout of Hogwarts and depicts the movements of every person's movement across the castle and grounds.

Mud Blood - a derogatory name for a wizard with muggle parents

Muggle - a human who has no magical gifts or talents. An ordinary person. Not a witch.

Quidditch - A popular wizarding game played on broom sticks in which players try to shoot a series of balls at opponents and through scoring hoops. The most important ball in the game is the "Golden Snitch".

Patronus - A spell used to repel Dementors, and some other magical beings, that produces a bright white or silver apparition in the shape of an animal. The animal is unique to the spell caster.

Sorcerer's Stone - A stone that produces the Elixir of Life, granting all who drink it eternal life. Can also turn metals into gold.

Sorting Hat - A magical artifact, a hat that is used to sort students into their houses at Hogwarts. The hat is able to talk and often composes and performs songs before sorting students.

Squib - A muggle born to wizarding parents. Very rare. http://www.hp-encyclopedia.com/index.php/glossary