A slot is a narrow notch or opening, such as a keyway in a piece of machinery or a slit for a coin in a vending machine. A slot is also a position in a series, sequence, or group, especially a numbered one.
Historically, slot machines used mechanical reels to display and determine results. Each reel had 103 = 1,000 possible combinations, but the number of combinations on each spin was limited by the fact that the reels had to turn physically. In modern video slots, the number of possible outcomes is much greater. However, the machine must still rotate the reels and pay out winnings only if certain symbols appear in a given combination.
In air traffic control, a slot (also known as a “slot time”) is an authorization for an airplane to take off or land at an airport on a specific day during a specified period of time. Airlines compete to secure slots at very busy airports in order to minimize air traffic delays caused by too many flights trying to take off or land at the same time.
In football, a slot receiver is a wide receiver who lines up close to the middle of the field. They tend to be shorter and faster than traditional wide receivers, but their size and speed make them a big target for defenses. They must have excellent blocking skills because they are usually responsible for blocking nickelbacks, safeties, and outside linebackers on passing plays and for sealing off the ball carrier on running plays such as sweeps and slants.