What Is a Slot?

A slot is a specific position within a group, sequence, or series of things. It can also be a place or time in an activity, or a position of employment. It is sometimes used in military vocabulary, as a synonym for patrol or guard duty.

A narrow notch, groove, or opening, as in a keyway or slit for a coin in a machine. Also: any of various openings in the wing or tail surface of an airplane, as for a control device, auxiliary airfoil, etc.

In computing, a hardware element that allows a program or data to access memory or other resources. A CPU contains many slots to hold the programs and data it executes. A computer can have several slots in its system, and each slot is assigned a different speed for its operation. A slow slot is more likely to fail, while a fast one is less likely to fail.

An individual unit of time in a calendar, in which events occur. The term is most commonly used for days of the week, but it can also refer to an entire month or year, a single season, a business day or a period of time in sports. A time slot may be scheduled, planned, or unscheduled.

On a mechanical slot machine, a fixed number of symbols appear on each physical reel, with the chance that any given symbol will land on a pay line determined by the payout table. In electromechanical machines, this payout table was listed above and below the area containing the spinning reels. On modern video slot machines, this information is displayed on the machine’s screen.

When a job uses too many slots and causes other jobs to wait for their own turn, the extra capacity is called “excess slot usage.” If this continues to happen, your system can be delayed. To prevent this, you can limit the number of slots that each job is allocated. Excess slots are not billed directly to you but are included in your overall slot usage with the exception of certain detailed execution statistics.

A slot is also a term used to describe the amount of money paid by a casino for a slot machine spin that produces no winning combination. This is a common misconception, as the probability of a particular symbol appearing on a pay line depends on its relative frequency on each of the slot machine’s physical reels and not on the chances of other symbols being present in a spin.

In airport coordination, a slot is an authorization to take off or land at a specific airport on a specified date and time during a particular window of time. This method of scheduling is used to avoid repeated runway delays, especially at busy airports. In the United States, the FAA allocates slots to commercial flights through a process known as slot allocation. In Europe, the European Union has a similar system for allocating slots to air traffic.