What is a Slot?

A narrow depression, perforation, or aperture, especially one for the reception of a piece that fits or slides in it. In computer hardware, a slot is a device for holding an expansion card.

In a computer, a slot is an opening or hole in a motherboard into which a PCI, AGP, or ISA card can be inserted. Also, a slot can refer to a reserved place in a computer for memory, such as the DIMM slots found on modern laptops.

The term “slot” can also refer to a specific place or time in a schedule or program, such as the 2 p.m. slot that the barber has scheduled for my haircut. Similarly, a slot can also mean the position in a tournament that a player holds after several rounds of play.

A slot in the sense of an occurrence or a position is also a feature of many casino games, particularly those based on a reel. When a slot is played, a random number generator (RNG) establishes the odds of each stop on a particular win line. Unlike mechanical slot machines, which relied on the door switch and other mechanisms to detect tilting, electromechanical slot machines were programmed to weight certain symbols to prevent cheating by tampering with the machine or predicting their location. Today, all slot machines use a computer-based RNG to establish the odds of winning and the order in which those symbols will appear on a given reel.