A casino is an establishment for certain types of gambling. Casinos are often built near or combined with hotels, restaurants, retail shops, and other entertainment venues. Some casinos are also known for hosting live entertainment events, such as stand-up comedy and concerts.

The exact origin of gambling is unknown, but it has been a part of almost every culture throughout history. Ancient Mesopotamia, China, the Roman Empire, and Elizabethan England all had some form of gaming. Today, gambling is legal in 40 states.

Modern casinos are massive complexes that offer a wide variety of games and amenities to their guests. The largest casinos can feature a five-star hotel, Michelin-starred restaurants, designer shops, and top-billed entertainment shows. Guests can gamble at casino tables and slot machines, play poker, or watch a sports game in the comfort of their room.

In the United States, there are more than 1,000 casinos. Las Vegas has the highest concentration of casinos, followed by Atlantic City and Chicago. The majority of casino revenue comes from the sale of lottery tickets, slot machines, and table games. Other significant sources of income are sports betting and the operation of hotel and restaurant facilities. Because of the large amounts of money handled in a casino, both patrons and employees may be tempted to cheat or steal, either in collusion or independently. For this reason, casinos employ a variety of security measures. Security cameras are located throughout the facility, and most casinos have a police department to enforce the law.