A narrow notch, groove, or opening, such as a keyway in machinery, a slit for a coin in a vending machine, or an area on a plane wing or tail that accommodates a control surface. Also: (computer) A location on a disk or other storage medium into which data can be stored; an area of a program into which instructions can be loaded, saved, and executed. From Middle Low German schot, from Middle Dutch schot.

In electromechanical slot machines, the symbols on a payline are arranged according to a pay table that specifies how much the player earns if a specific combination of symbols appears on the pay line. The pay table is usually printed on or near the machine, and may also be accessible in a help menu or similar feature. Modern video slots use microprocessors to assign different probability weightings to each symbol on each reel, so that winning symbols appear more frequently than losing ones.

A good online casino will typically list the return to player percentage for its slot games, along with any other important information, such as maximum bets and jackpot sizes. In addition, reputable casinos will offer bonuses for playing slots, such as free spins and match-up bonuses. These can be very useful to new players, but be sure to read the terms and conditions carefully. Often, these bonuses come with significant wagering requirements that must be met before the player can withdraw any funds.