A casino, also known as a gambling hall or a gaming house, is a place where people can gamble on games of chance or skill. Most casinos offer a wide variety of gambling activities, including poker, blackjack, craps, and roulette. Unlike lotteries and Internet gambling, casinos have an in-person component that requires players to interact with other people. The casino industry has evolved into a massive business that provides jobs and economic stimulus to many states. It is estimated that the global gambling market was worth US$45 billion in 2010.

Casinos earn billions of dollars each year from patrons who wager on games of chance or skill. This money goes to the companies, investors, and Native American tribes that operate the casinos, as well as to state and local governments in the form of taxes and fees. However, studies indicate that compulsive gambling generates a net loss to the community, with addicts costing casinos up to 25 percent of their profits.

In addition to gambling, a casino offers entertainment and other amenities to attract and retain customers. Its restaurants and buffets serve food and drinks. Its bars and lounges feature live music or DJs, and stage shows provide dramatic scenery. The biggest casinos have thousands of slot machines and tables. Some offer private rooms for high rollers or VIP customers who want to have quiet sessions without the distraction of other patrons. Many casinos have frequent-flyer programs that tally player points and allow them to redeem them for free slot play or other amenities.