A slot is a narrow notch, groove or opening such as a keyway in machinery or a slit for a coin in a vending machine. A slot is also a position within a group, series or sequence.

An airport slot is a time period during which an airline can operate on a congested runway or airport. A slot can be bought and sold, and can be used by different airlines at different times. This is a popular way to maximize revenue, and can be used by airports that are under capacity or those with multiple runways but limited space.

The first video slots were invented in Las Vegas in 1976. They were changed a bit to prevent cheating, and then approved by the gaming commission. They work differently than mechanical slots, utilizing a computer to read the physical stops on each reel and the corresponding virtual ones, and then determining the odds of hitting a particular sequence. When a winning combination is hit, the game shows the player their winnings.

When playing a slot machine, the “credit meter” is displayed on the screen. It is usually a seven-segment display, but on some video machines it may use stylized text. It can be lit to indicate change needed, hand pay requested or a problem with the machine. The credit meter is not the same as the amount of money that can be played, which varies by casino and can range from 90% to 97%.