A casino (plural: casinos) is a gambling establishment equipped with gaming devices. It also offers various entertainment options, such as shows and live sports events. Its staff are trained to deal with customer inquiries and questions.

The primary way that casinos make money is by taking a percentage of each bet placed on games with some element of skill, such as blackjack and roulette. This percentage is mathematically determined by the house edge, which varies from game to game; however, in poker and other games where players compete against each other, casinos earn money via a commission, or rake, on each bet.

As well as the money that is deposited by customers, casinos also generate income from the sale of alcohol and snacks. Moreover, they may also earn revenue from the rental of space to outside companies for special events and from a small percentage of the turnover of slot machines.

Due to the large amounts of currency handled within a casino, both patrons and employees may be tempted to cheat or steal, in collusion or independently; therefore casinos employ a number of security measures. These include a physical security force and specialized surveillance departments that operate closed circuit television systems known as eye in the sky.

In addition to the aforementioned methods, modern casinos use technology to superintend each game. This is done with the help of a computer that monitors each slot machine and identifies statistical deviations. These deviations are then flagged for a human supervisor, who checks them against previous results and verifies that the machine is functioning correctly.