Slot (plural slots) is an online casino game that mimics the popular machines found in brick-and-mortar casinos. They come in many themes and varieties, but they all share the same basic game mechanic: a user spins the reels to match symbols in combinations that appear along what is known as a payline. A winning combination pays out a prize based on the amount of coins a player has placed into the machine. Increasing the number of paylines increases the chances of hitting a jackpot, but also increases the amount that a player must spend to play.

A specific time and place at which an aircraft may take off or land, allocated by an airport or air-traffic control authority: “40 more slots were available for the new airline at U.S. airports”. Also:

An advantage play method involving a machine that has multiple occurrences of a bonus symbol that triggers a specific game feature, often one with significant payouts. This can be accomplished through a number of different ways, but usually involves careful study of the game rules and the machine’s pay table. These types of games are often referred to by gamblers as “banking” machines.

A slot is a dynamic placeholder that either waits for content to be added to it (a passive slot) or responds to a trigger by adding content to it (an active slot). Slots work with scenarios and renderers to deliver content to a page; they also define several important properties for offer management.