When most people think of a casino, they envision a massive hotel and entertainment complex in Las Vegas, with bright lights, games of chance, and a host of live performances. But in reality, casinos are much more diverse. The term can be used to describe any place that offers gambling activities, from a small corner in a bar to an entire building.

Most casinos focus on generating revenue by offering a variety of games and providing attractive atmospheres. They also offer perks to encourage gamblers and reward those who spend the most money. This is called comping. Comps can include anything from free food and drinks to discounted hotel rooms and shows. During the 1970s, many Las Vegas casinos gave out travel packages, cheap buffet passes, and show tickets as incentives to attract and keep gamblers.

Casinos make money by ensuring that the house always has a mathematical advantage over players, a concept known as expected value or house edge. In addition to this, some casinos earn a commission from games that have an element of skill, such as poker, in which the house takes a rake from each player. Casinos employ mathematicians and computer programmers to work out the expected values of their various games, as well as other specialized personnel.

In March 2002, Gemini Research reported the results of a survey of Nevada residents who self-reported participation in casino gambling. Slot machines were the most popular game, followed by card games, and then table games. Keno and bingo were far less popular, with only 6% of the respondents declaring them their favorite games.