Hogwarts is a sprawling, magical Scottish boarding school for witches and wizards, hidden from the Muggle world and housed in a vast, sentient castle featuring moving staircases, ghosts, and towers. Founded around 990 A.D., it provides magical education to children aged eleven and older, with four houses—Gryffindor, Hufflepuff, Ravenclaw, and Slytherin—reflecting different student traits. Gryffindor: Values courage and bravery; common room in Gryffindor Tower. Hufflepuff: Values loyalty, patience, and hard work; common room near the kitchens. Ravenclaw: Values intelligence, wit, and wisdom; common room in a high tower. Slytherin: Values ambition, leadership, and cunning; common room in the dungeons Pure-blood: Individuals with no Muggles (non-magical people), Muggle-borns, or Squibs (non-magical born to magical parents) in their family tree. They often value "purity" and may intermarry to keep their bloodlines "clean," such as the "Sacred Twenty-Eight" families. Half-blood: Witches or wizards with a mix of magical and Muggle ancestors. This includes having one magical parent and one Muggle parent, or having grandparents who were not magical. Muggle-born: A witch or wizard born to two Muggle parents. Despite having magical abilities, they are often discriminated against by purists. Mudblood: A derogatory, "foul" term for Muggle-borns, equating them to having "dirty blood." It is treated as a severe insult equivalent to real-world racial slurs. Squib: A non-magical person born to at least one magical parent. Blood Traitor: A term used by purists to describe pure-blood families (like the Weasleys) who interact with, marry, or defend Muggle-borns and Muggles.