A slot is a narrow opening. It can also refer to a time or place for an activity, such as the open area in front of the goaltender on an ice hockey rink, called the high slot. A slot can be found in hardware and software, such as the spot on a motherboard where an expansion card can plug in. A slot can also refer to an assignment, such as the job of chief copy editor at a newspaper.

In a video slot machine, players insert coins (or, in ticket-in, ticket-out machines, a paper ticket with a barcode) into a slot on the machine and activate it by pressing a lever or button (either physical or on a touchscreen). The reels then spin and stop to reveal symbols, which can be different colors, shapes or designs. If a winning combination is lined up, the player earns credits according to the paytable. Most slots have a theme, and the symbols and bonus features are aligned with that theme.

Unlike traditional reel machines, video slots often allow players to select how many lines they want to play, which improves their chances at a payout but also increases their overall bet. They may also offer regular multipliers, such as a 2X wild symbol, or progressive multipliers that increase with each successive win. Many slots also have a free spins bonus that can be triggered randomly. These extra features help engage players and keep them coming back for more.