A slot is a narrow notch or groove, especially one for receiving something, as a keyway in a door or a coin in a vending machine. It is also a position in a group, series, or sequence.
A slots game is played with a computer or electronic device that has reels that spin and stop to rearrange symbols, awarding credits based on the pay table of the machine. The symbols vary according to the theme, but can include traditional fruit, bells, stylized lucky sevens, and other objects. Most slots have a specific style or location, and bonus features are aligned with the theme.
Players insert cash or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode into the designated slot on the machine and activate it by a lever or button (physical or virtual). The reels then spin, and when a winning combination of symbols appears on the pay line, the player is awarded credits based on the pay table. The odds of winning differ from machine to machine, and some have caps on how much a jackpot can be won.
In software programming, slots are a component programming mechanism that enable a class to receive signals from other classes. Signals are normal member functions that can be emitted anywhere in the program, and they connect to slots through an implicit sender-receiver pair. Emitting a signal that is connected to multiple slots is approximately ten times slower than calling the receivers directly, with non-virtual function calls.