A casino is a facility for certain types of gambling. Casinos are often built near or combined with hotels, restaurants, retail shops, and other tourist attractions. In some countries, casinos are licensed and regulated by gaming authorities. Security is also a concern in casino operations, as patrons and staff may be tempted to cheat or steal, either in collusion or independently. Various measures are used to deter such behavior, including cameras and other technological equipment. Casinos also enforce rules of conduct and behavior. For example, casino employees are trained to watch for players removing chips from the table without paying.

The etymology of the word is unclear, but it is believed to have evolved from a Latinized version of an Italian word meaning “public hall” or “social club.” It was not until the second half of the 19th century that large public casinos were opened in Europe and America.

Casinos feature a variety of games of chance and some skill. Most games have mathematically determined odds that ensure the house has a constant advantage over players. This is sometimes expressed as the house edge or expected value. Some games, such as baccarat, are popular in many countries and casinos, while others are restricted to specific markets.

Casinos have become a major source of revenue for some nations. In the United States, Las Vegas leads in overall gambling revenues, followed by Atlantic City and Chicago. The number of casinos continues to grow as more states legalize them.