A slot is a narrow opening in a machine or container, for example, one that accepts coins. It can also refer to a time or place when an activity can take place, such as a flight time slot:

In a slot game, players insert cash or in some cases tickets with value printed on them (in “ticket-in, ticket-out” machines) into a machine’s designated slot. The machine then spins the reels and, if matching symbols line up along a payline, awards credits based on the slot’s payout table. Most slots have several paylines and offer different odds of winning, so players should always check a machine’s pay table before starting play.

Bonus rounds:

Most slots come with a variety of bonus features that give players additional ways to win other than traditional paylines. These can include free spins, a pick-and-win game, or even an entirely separate spinning wheel that allows players to choose from multiple prizes. Some of these bonus rounds require a certain amount of money to trigger, and this information will be clearly displayed on the machine’s pay table. It’s important to know about these features before choosing a slot, as they can add excitement and variety to the gaming experience.