A slot is a position in a series, sequence or group. It also means an opening in something, such as a door or window.
In a slot machine, players insert money or, in the case of “ticket-in, ticket-out” machines, a paper ticket with a barcode into a designated slot and activate it by pressing a lever or button (either physical or on a touchscreen). The reels spin and stop to rearrange symbols. If the symbols match a winning combination, the player earns credits based on the game’s paytable. The paytable is traditionally displayed on the slot machine itself, usually in the form of an actual table with columns and rows that display various combinations and payouts from highest to lowest at the top, left to right.
While the technology behind slot machines has changed dramatically over the years — classic mechanical designs have been supplanted by computer-controlled models that can handle thousands of mathematical calculations per second — the basic principles remain the same. The player pulls a handle to rotate a series of reels (typically three) that have pictures printed on them. Winning or losing depends on whether the winning pictures line up with a pay line, which is a line that runs through the middle of the viewing window. A win is determined by matching certain combinations of symbols in the pay line, and the amount won is based on the number of matching symbols in a row (certain single images are winners as well).