A casino is a facility where people can gamble using cash or other types of monetary value. A casino also offers entertainment and other events to its visitors. Casino gambling is popular around the world and is legal in many places. Casinos are most often built near or on water. The precise origin of gambling is not known, but it is generally believed to be an ancient human activity.

There are three general categories of casino games: gaming machines, table games, and random number games. Gaming machines, such as slot machines and pachinko, are operated by computerized mechanisms. In contrast, table games such as blackjack and craps involve a live dealer and are conducted by croupiers. Random number games are based on the selection of random numbers, either by a computer program or by other means such as dice.

Most casino games provide a predictable long-term advantage to the house, known as the house edge. However, some casino games have a skill element, and players who possess sufficient skills can reduce the house edge to zero or even make a profit. These players are referred to as advantage players.

Most casinos have a physical security force and a specialized surveillance department to protect the property, patrons, and employees from theft and other criminal activities. The size of the security force varies, depending on the size of the casino and the level of risk. In addition to physical security, modern casinos use closed circuit television to monitor the gambling area and detect any suspicious or unauthorized activity.