A casino is a place where people can gamble on games of chance. There are three general categories of casino games: gaming machines, table games, and random number games. Gaming machines are games of chance operated by a computer, and the results of these games are based on the selection of random numbers or on other data. Table games involve one or more players and are conducted by casino employees known as croupiers or dealers. Random number games are based on the selection of random or pseudorandom numbers by a computing device.

Gambling has been around for millennia in almost every culture worldwide and is a popular source of entertainment. Modern casinos are a major tourist attraction and many cities have become well known as gambling centers. The Monte Carlo Casino in Monaco, for example, is internationally recognized. Many European countries changed their laws during the latter part of the 20th century to permit casinos, and some such as Belgium, Switzerland, and Denmark have a large number of casinos.

Besides slot machines and tables, a casino can also offer its patrons other things to do such as shopping, dining, or seeing a top-billed entertainment show. Some of the largest casinos have several upscale amenities such as Michelin star restaurants, designer shops, and high-end entertainment shows that feature circus acts and musicians on their rise to fame. The Bellagio in Las Vegas is one such example and has been voted as the best casino in the United States.