The fictional sport played by Harry Potter at Hogwarts is Quidditch.
Quidditch is played by two teams of seven players flying on broomsticks. Each team has three Chasers, two Beaters, one Keeper, and one Seeker. The players use four balls: one Quaffle, two Bludgers, and a Golden Snitch.
Harry plays as Seeker for the Gryffindor team. The Seeker’s main task is to catch the Golden Snitch, which usually ends the match and awards 150 points. A team can still lose after catching it, so the Snitch does not automatically determine the overall winner.
Rowling has said that the name was inspired by “Kwidditch,” a term she invented while developing the fictional game. A real-world broomstick sport later adopted the name, although the international sport has changed its terminology in response to trademark and inclusion concerns.