A slot is a narrow notch, groove, or opening, such as a keyway in a piece of machinery or a slit for a coin in a vending machine. It is also a position in a group, series, or sequence.
A football player who lines up in the middle of the field on running plays is called a slot receiver, and players like Tyreek Hill or Brandin Cooks are making them more prominent in the NFL because they can stretch defenses vertically by running routes that go from end to end rather than in a straight line. They are also good at running short routes, such as slants.
The term slot is also used to refer to a position in a computer program or a system. For example, a program may run in two slots (one for the kernel and one for user-level applications). A system can also have multiple slots for different types of memory.
In a computer, a slot is a site where you can insert a printed circuit board. These are often called expansion slots because you can install additional boards to expand the capabilities of a computer. They are not to be confused with bays, which are sites in a computer where you can install disk drives.
Traditionally, electromechanical slot machines had tilt switches that would make or break a circuit when they were tampered with. Modern slot machines have microprocessors that detect these tampering attempts and may lock out the operator or shut down. Moreover, the computers that run modern slot machines can assign a different probability to each symbol on each reel, so it might appear to a player that a certain symbol was “so close” to hitting, whereas in reality it was unlikely.
A slot is a particular time or date that an aircraft, train, ship, or vehicle will be in a fixed position. It is usually a small window of time, and it can be reserved weeks in advance. In addition, airlines can reserve time slots to land or depart from Level 3 airports. A passenger can book a seat on an airplane or train using an online reservation system, and the airline will then allocate a specific time for that flight or train to arrive or depart from the airport. This process is known as scheduling. In many countries, air traffic control uses a system of slots to manage the flow of planes and trains in order to ensure that there is sufficient capacity for all flights. The concept of slots originated in the United Kingdom, where the concept of a slot was first adopted by British Airways. Other airlines soon followed suit, and today, virtually all large airports use slots to schedule aircraft arrivals and departures. This is the same system that is currently used by most major train and bus companies. In addition, there are several international standards for slot allocation. The most widely used is the ICAO Slot Allocation and Reservations System, which is supported by various software systems.