A slot is a narrow opening in a machine or container. It can also refer to a position in a sequence or schedule.

In a slot machine, the player inserts cash or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode into a designated slot on the machine to activate it. The machine then displays a series of symbols and pays out credits based on the combination of those symbols, as dictated by the paytable. The symbols vary by machine, but classics include fruits, bells, and stylized lucky sevens. Most slot games have a theme, and the symbols are aligned with that theme.

With a touch-screen interface, the new generation of video slots allow players to slide their finger across the screen to move objects and interact with the game, as well as to access bonus features. These can be simple mini-games that increase a player’s chances of winning, or they may be complex multi-level adventures that lead to progressive jackpots and other rewards.

In aviation, a slot is a specific time period when an airline may take off or land at an airport that is constrained. This is usually a result of runway capacity or parking space (such as at Heathrow). Airlines can purchase slots from the air traffic control authority, EUROCONTROL, in order to minimize delays and avoid unnecessary fuel burn.