A casino is a building that offers gamblers the opportunity to wager money and win or lose. Some casinos offer a wide variety of games, such as poker, roulette, blackjack and craps. Others focus on one type of game, such as baccarat. Casinos also offer entertainment, such as musical shows and lighted fountains. They can be found around the world.

Some casinos are open 24 hours a day. Some are surrounded by restaurants, shops and hotels. Most have security staff. Some have catwalks above the gaming floor that allow surveillance personnel to watch the action through one-way glass. In 2005, the National Research Council reported that about 51 million people visited casinos domestically—about a quarter of all adults over 21.

The casino industry relies on a number of different types of gambling games to bring in customers. Some are banked, such as blackjack, baccarat and craps, while others are not, such as poker. In a banked game, the house takes a percentage of each bet. In nonbanked games, the house only collects a fraction of the total amount wagered on the game.

Casinos also make their profits through the sale of drinks, food and merchandise. In some cases, casinos rent out rooms to high-end companies for meetings and events. They may also provide services such as spas and golf courses. In other cases, they may offer high stakes poker rooms, which attract professional players. Casinos are usually decorated in bright and cheery colors to stimulate the senses and help players lose track of time.