A casino is an establishment where gamblers place bets, play games and win money. Casinos are located around the world and are often combined with hotels, restaurants and other tourist attractions. Some casinos specialize in specific types of gambling, such as poker or horse racing, while others offer a full range of casino games and entertainment. There is no precise origin of gambling, but it has been present in almost all societies throughout history.

Modern casinos rely heavily on technology, with sophisticated systems for tracking wagers and overseeing the physical integrity of games. In some casinos, for example, betting chips have built-in microcircuitry to communicate with electronic systems in the tables to reveal minute-by-minute wagers; roulette wheels are electronically monitored regularly for any statistical deviation from their expected results; and slot machines use computers to monitor the game and payouts, eliminating the need for human dealers.

Because of the large amounts of money handled within a casino, there is always the risk that staff and patrons will cheat or steal. For this reason, many casinos spend a significant amount of money on security. In addition to a physical security force, most modern casinos have a specialized surveillance department with cameras that function like an eye in the sky, allowing security personnel to watch every table, window and doorway at once.

Some casinos also offer special inducements to high-volume players in the form of free food, drinks and hotel rooms. These are called comps. In addition, the most prolific casino players are often offered reduced-fare transportation and limo service for special events.