A casino is a gambling establishment offering games of chance to customers who pay money in exchange for the opportunity to win real cash or prizes. The casino industry is massive; it is estimated that the total global market for casinos and related gaming is about $231 billion. Casinos are mainly owned and operated by private companies or public entities such as cities or Native American tribes. They are also a major source of revenue for state and local governments.

In addition to gambling, casinos offer other entertainment options such as restaurants and bars, and some even have theatres. Many casinos create a stimulating atmosphere by using lights, sound, and scents to attract and retain gamblers. They often give out complimentary items, known as comps, to gamblers. Some casinos also have special security measures such as video cameras and sophisticated chip-tracking systems that enable them to monitor wagers minute by minute and quickly discover any statistical deviations.

Although most people who visit a casino do not intend to gamble, many find themselves playing on the tables or slot machines. In the United States, for example, a survey in 2003 found that 30% of poll respondents had visited a casino within the previous twelve months. These visits were primarily social in nature, with people going to casinos to spend time with friends or family. In addition, many of these individuals were willing to accept the risk of losing money. This is in stark contrast to the attitudes of Europeans, who are less accepting of casino gambling.