A narrow notch, groove or opening. Examples include a keyway in machinery and the slit for coins in a vending machine. Also, a period of time set aside for an activity: He booked a meeting for this slot in the daytime.

In a casino game, a slot is the space where a player inserts cash or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode. The machine then activates and spins reels that hold symbols and stops them to rearrange them according to a paytable when the player presses a button (either physical or on a touchscreen). When symbols line up along a winning payline, the player receives credits based on the amount of the bet. Symbols vary with each machine, but classic symbols include fruits, bells, and stylized lucky sevens. Most slots have a theme and feature bonus features aligned with that theme.

Many casinos have a policy against increasing the house advantage on their slot machines. They do so because they fear that such increases would cause customers to move to other casinos, which could result in significant losses. However, some studies suggest that arousal is not the only reason people enjoy playing slots. It may be that the games distract players from painful emotional experiences.

In the workplace, slot-based scheduling can help organize and monitor important deadlines and milestones. For example, health care providers may use time slots to book appointments with clients and then sort those appointments by appointment type, such as urgent care or routine check-ups. Using slots to track these important milestones can encourage open communication and transparency about team schedules and can support progress toward project objectives.