A casino is a building or room where people can play gambling games. It also includes a wide variety of other entertainment options, such as restaurants, bars and stage shows. In modern times, casinos are usually highly regulated and include features such as security cameras and electronic card readers to prevent cheating.

A major source of revenue for casinos is the house edge, a built-in advantage that ensures the casino will always make money. This advantage can be very small (less than two percent) or as large as six percent, depending on the game and how it is played. Slot machines are a classic example of this: players put in money, pull a handle or push a button and watch as bands of colored shapes roll on reels (either actual physical ones or a video representation of them). If the right pattern comes up, the player wins a predetermined amount of money.

The house edge is smaller in games such as poker, where players compete against each other rather than the house. However, in these games, the casino may still charge a fee to players called the rake.

Some casinos offer complimentary goods or services to patrons, known as comps. These can include meals, hotel rooms, show tickets and limo service. Many casinos also have generous welcome bonuses for new players.