A casino is a gambling establishment, where a variety of games of chance are played. It may also be combined with hotels, restaurants and shopping centers. It is not to be confused with a gambling house, which refers to a private home where people can play games of chance.
Modern casinos look like indoor amusement parks for adults, with lighted fountains, musical shows and elaborate themes to lure in customers. But the vast majority of their profits come from gambling. Slot machines, blackjack, roulette and other table games are the source of the billions that casinos rake in every year.
While some players are able to beat the odds, most do not. That is why casinos spend so much money on security. Security starts with employees monitoring games and patrons to make sure that all is as it should be. Dealers can easily spot blatant cheating (palming, marking, switching cards or dice). Pit bosses and table managers have a more comprehensive view of the game, watching for betting patterns that could indicate collusion between patrons.
The security is complemented by electronic systems that can quickly detect any statistical deviation from expected results. Some casinos are so heavily monitored that they can even tell when a player is bluffing. The mob used to control a lot of the biggest casinos, but when real estate developers and hotel chains got in on the act with deep pockets, they bought out the gangsters and began operating casinos without the need for Mafia supervision.