A casino is a public room where the playing of gambling games (such as roulette, baccarat, blackjack, poker, and slot machines) is the principal activity. It may also refer to a large hotel or similar establishment that features one or more such rooms as its primary attraction. The term is also commonly used in the United States to describe an online gambling business that offers such games.

Gambling in some form or another has been part of human society for millennia. Evidence of dice throwing dates back to 2300 BC, while the earliest recorded card game is believed to be a variant of bridge called trente et quarante, which first appeared in the 14th century. In modern times, casinos have become an important source of entertainment and tourist revenue.

While some casinos offer a wide range of games, others specialize in specific types of gaming. For example, some casinos focus on table games such as baccarat and blackjack, while others are known for their sports betting facilities. In addition to the gaming floor, many casinos have restaurants and bars. Some are located in exotic locales such as Venice, Monaco, and Singapore. In order to make the most money possible from their patrons, casino managers must have a keen understanding of the house edge and variance of each game offered. Consequently, some casinos employ dedicated mathematicians to analyze and optimize their game mix. These professionals are often referred to as gaming mathematicians or casino analysts.