A slot is an opening, hole or groove into which something can be inserted. He dropped a coin into the slot and dialed. A slot can also refer to a position, such as the high slot in hockey, where a defenseman can take a blistering slap shot. A slot is also a place in a schedule or program, where an activity can take place. Visitors can book a time slot a week or more in advance.

A slot can also be a compartment in a ship or aircraft that can hold cargo. Airlines use slots to limit the number of planes that can land or take off at busy airports. This helps prevent repeated delays that can occur when too many flights try to take off or land at the same time.

Modern slot machines look much like the classic mechanical designs, but they work on different principles. A player inserts cash or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode. A handle then spins the reels and, if the machine displays matching symbols along a pay line in the center of the screen, the player wins credits based on a fixed payout table.

Many video slots are themed after popular TV shows, movies and other entertainment, and they often include bonus games that let players win free spins or returns on their bets. Some of these games are so popular that they have become a major source of online gambling revenue for operators. But research suggests that people who play these machines may reach a debilitating level of addiction more quickly than those who play traditional casino games.