A slot is a position where something can be fitted. A computer motherboard may have several slots for expansion cards, which can be used to add memory or other functions to the system. A slot can also refer to an area of a video card that contains the graphics circuitry. A slot is a term that can also be applied to a specific type of machine, such as a slot car.

In gambling, a slot is a machine that pays out credits based on the symbols it displays when activated by a lever or button (physical or virtual) or, in ticket-in, ticket-out machines, by pressing a barcode displayed on a screen. Some slot machines pay out credits in a random sequence, while others are programmed to follow a particular pattern. Bonus features can also be present, which increase the chance of winning by activating additional reels or other special symbols.

Whether or not a slot machine is programmed to pay out on a particular pattern depends on the odds it provides, which are determined by its random number generator. The RNG runs through a set of numbers every millisecond, and when triggered by any input (from a button being pushed or a handle pulled) it sets a new number that corresponds to a particular combination of symbols on the reels.

Some players claim that it is possible to manipulate the odds of a slot machine by pressing buttons at certain times, rubbing machines in a particular way, or tracking “near misses” to determine when a machine will payout. These superstitions are largely without merit, as the random number generator ensures that each spin is independent of any previous results.