A space on a computer or other device in which a particular type of object can be stored. For example, a CD-ROM may have four slots for saving data.

The word slot can also refer to the position of a player on a team in field hockey or ice hockey, where it is the fourth position after the leader and two wingmen. It can also refer to a time period in which a particular event takes place, such as a television show or sports game.

Until the 1960s, when electromechanical machines began to replace mechanical ones, casino gambling focused on table games and slots were considered frivolities that distracted wives of gamblers. However, in the 1980s, the introduction of microprocessors allowed manufacturers to weight particular symbols on each reel so that they appeared to appear more often than they actually did. This led to the resurgence of slots and increased jackpot sizes, as well as diagonal and zig-zagged combinations that speeded up play.

Psychologists have found that people who play video slot machines reach a debilitating level of addiction three times more rapidly than people who play traditional casino games, even when they have no previous history of gambling problems. They also lose control of their behavior more quickly, and the effects of their gambling are more pronounced than those of other addictive behaviors.