A slot is a narrow notch, groove, or opening, such as a keyway in a machine or container, or a slit for coins in a vending machine. A slot may also refer to a position in a group, series, or sequence. The phrase is commonly used in the context of computer programming, where it refers to a specific place in a queue for executing an operation. The term is also used in a more general sense, to mean any location in an array or list that can receive data or instructions.
A slot can also be a device on a computer that allows a user to insert tokens or paper tickets, or a virtual coin, in order to make the machine pay out credits. The machine then evaluates the ticket or token, and displays a message on the screen to indicate the result. In some cases, the machine will also display a percentage of the total amount of credits that the player can win. A slot is sometimes called a hopper because it holds many coins and tokens.
In football, a slot receiver is a wide receiver who lines up on the outside of the field and is expected to cover multiple defenders. They are fast enough to run past defenders and catch the ball in stride, but they must also be tough enough to absorb contact. Slot receivers are often used on pitch plays, reverses, and end-arounds.
The term slot is also used to refer to a particular position in a computer program, or in the case of a physical device, the time and space allocated for it by the device’s operating system or hardware. For example, an operating system might allocate a specific number of slots for running applications and reserve others for system services. The number of available slots is usually specified in the operating system’s system configuration or in a boot loader.
If a slot has been reserved, the machine’s operating system will notify the user with a message on the screen, or with an audible alarm (if the machine is equipped with an audio output). Some modern electronic slot machines have sensors that detect tilt, and a sensor that determines if there is a paper jam. If the sensor is triggered, the machine will stop paying out, and may display a warning message or an error code on the display. Older electromechanical slot machines had “tilt switches” that would trigger the machine’s alarm if they were tilted or otherwise tampered with.
A slot can also refer to a time and place that has been allocated for an airplane or other vehicle to take off or land, as authorized by the airport or air-traffic control authority. The slot may be reserved ahead of time by passengers, or it may be allocated as the plane waits to clear a runway. In the latter case, it is sometimes difficult to obtain a slot when you want one, as the airline may have already reserved them all.