A casino is a gambling establishment, where people gamble money on games of chance. The games may have an element of skill, as in blackjack and video poker, but the primary way casinos make money is by taking a percentage of the bets placed by patrons. This is called the house edge. Casinos also earn money by giving away complimentary items, or comps, to players.
Casinos offer a lot of free stuff to keep people playing as long as possible, including food, drinks and hotel rooms. The reason they can do this is that, over time, the casinos will always have a built in statistical advantage. This advantage can be a small amount, but it adds up over the millions of dollars that are bet each day. This gives the casino enough money to build impressive structures like fountains, pyramids and towers.
Because there is so much money changing hands in a casino, cheating and theft are common problems. For this reason casinos use sophisticated surveillance systems. For example, some casinos have catwalks in the ceiling that allow security personnel to see directly down on tables and slot machines through one-way glass. Other technologies are used to track betting chips with microcircuitry, and to monitor roulette wheels for any deviations from their expected results.
Critics of casinos say the profits generated by gambling addicts offset any economic benefits they bring to a community. They also argue that the local economy loses out when gamblers shift spending from other forms of entertainment.