What Is a Slot?

A narrow opening, as in a door or window. Also, a position in a series or sequence, especially in a hierarchy or organization: He was given the slot as chief copy editor.

In electromechanical slot machines, a slot is an area on the reels that holds a number that corresponds to the machine’s pay table. Each slot has a specific pattern of symbols that appear on it, and each symbol is weighted to have a different chance of appearing as part of the winning line. Each machine has its own payout chart that shows which symbols earn credits, and these charts are often displayed above and below the slots. On video machines, the slots are usually contained within a help menu.

Traditionally, players dropped coins into slots or activated games by pressing buttons. But this changed in live casinos when bill validators and credit meters were introduced, and online casino sites began offering advance deposits and “virtual” tokens instead of cash. The introduction of the slot also made it easier to blur the distinction between real money play and playing for free.

In aviation, a slot is an authorized time or location for an aircraft to take off or land. It’s a tool used by airports and air traffic controllers to manage congestion, particularly at busy hubs, and avoid the repeated delays and wasted fuel that can occur when too many flights try to take off or land at the same time.