A slot is a narrow opening in something, such as a door or machine. It can also refer to a time of day on a calendar, for example: “I have a meeting from 11:00 to 12:00.”

A slots system keeps takeoffs and landings spaced out, so that air traffic controllers can manage aircraft flow safely. The name is also used for a type of online casino game that uses similar principles to manage the flow of credits between players and the house.

In slot games, symbols are arranged on reels to form combinations that award prizes based on the pay table. They typically follow a theme and include classic icons, such as fruit, bells, stylized lucky sevens, and other symbols related to the theme. Some slots also feature bonus features that add an extra element to the game play.

To win at slots, you must understand the rules and how they work. Many online casinos offer a help section that can explain the rules of slot games, including the RTP (return to player percentage), which is a theoretical number that shows how much a machine may payout over an extended period. You should also check out the minimum and maximum bet amounts before playing, as these will limit your potential winnings.

In mechanical slot machines, the random-number generator assigns a probability to each symbol on each reel. When a signal is received — whether from a button being pressed or the handle being pulled — the microprocessor sets that number, and the reels stop on the corresponding combination. Higher-paying symbols, such as jackpot symbols, have fewer stops and occur less frequently, making it more difficult to line up three or four of them on a payline.