A narrow depression, groove, notch, or slit, esp. one for receiving or admitting something, as a coin in a slot machine or a letter in an envelope. Also, a position in a series or sequence: The TV show was scheduled for the eight o’clock slot.

The early mechanical machines had a lever that you pulled to activate them, but modern ones use random number generators and operate without a lever. Regardless, they still look like the old machines and work on similar principles. To win, you must line up symbols on a pay line (typically a row of three) that run across the center of the window. Each reel has a different set of symbols, and the amount you win depends on which ones align with the pay line.

Charles Fey improved on Sittman and Pitt’s design with a machine that allowed automatic payouts and had three reels, making it easier to win. He also replaced the poker symbols with more appealing icons, including diamonds, spades, horseshoes, hearts, and liberty bells. This increased the potential combinations and made it possible to get a large jackpot by aligning all three Liberty bells in a row. This became known as the “Stairway to Heaven” jackpot, and it is still a big draw for many people to visit casinos.

A slot is a narrow depression in the side of a vehicle, machine, or other object into which something can be inserted. A car’s door, for example, has a slot at the bottom where the key fits into. Similarly, the slot on the side of a computer case is where a RAM disk sits. The slot also provides a place for airflow, preventing dust or moisture from collecting in the slot.

In aviation, a slot is an allocated time and place for an aircraft to take off or land, as authorized by the air-traffic controller. A slot is usually reserved for larger commercial aircraft, but smaller regional aircraft may share a slot with other aircraft. For this reason, slots are often limited and tightly controlled, leading to delays for passengers and huge fuel savings for airlines by keeping aircraft on the ground when they could be in the air.

The word “slot” is related to the idiom “to slip into place,” which means to fit or slide into a position. For example, you might say, “She slotted her ideas into the theory.” These examples have been automatically selected and may contain sensitive content.