A narrow opening or groove that is designed to fit a piece of hardware, such as a lock, a key, or a screw. In computer science, a site in a motherboard or other computer hardware where an expansion board can be inserted. Slots are different from bays, which are sites where disk drives can be installed.

In casinos, a machine with reels that spin and display symbols when a button (or, in older machines, a lever) is pressed or a barcode is read. The symbols may represent objects, card letters or numbers, or other images based on the theme of the game. Most slots have a pay table that lists the number of credits a player will earn if certain symbols line up on a pay line.

Online slot games often have themes that harken back to a specific period or culture, such as pirates or ancient Rome. These games are also known for their visuals, such as colorful symbols and graphics that evoke a particular style or location. Some even feature sound effects and animations that add to the gaming experience. Slots are one of the most popular forms of casino gambling, and their popularity is surging to the point that many people now prefer them over live games like blackjack or roulette. When evaluating a new slot machine, it is helpful to know how the machine pays out before making a decision. This information can be found by plugging the name of the game and “slot” into a search engine.