A slot is a narrow opening in a machine or container that can be used to accept coins. It may also refer to a space or time in a schedule or program, such as when you can book a flight or take off from an airport.

When you play an online slot, you’ll insert cash or a paper ticket with a barcode (known as TITO on some machines) into the designated slot, then spin the reels and watch them stop to reveal symbols. Matching up these symbols on a payline determines whether and how much you win. The symbols vary depending on the game, but classic icons include bells, stylized lucky sevens, and fruit. Most slots have a theme, with bonus features aligned to the theme.

The random number generator (RNG) that powers a slot machine creates a sequence of numbers every millisecond, which is then used to select the stops on the reels. When you see the reels spinning, it’s only because the RNG has already selected them and is showing them to you as a courtesy. You can’t predict the outcome of a spin, but you can learn about the odds of winning by reading the pay table on the machine’s screen. It will tell you the symbols and payout amounts for matching combinations, including how much you’ll get if you land three or more of a certain symbol. You can also find rules for using Scatter or Bonus symbols.