A casino is, in the modern sense of the word, a facility that houses and accommodates certain types of gambling activities. Casinos are most commonly built near or combined with hotels, restaurants, retail shopping, cruise ships and other tourist attractions. Some casinos are known for hosting live entertainment events, such as stand-up comedy, concerts, and sporting events. Today, there are more than 4000 casinos worldwide. The precise origin of gambling is unknown. The Chinese recorded the first official account of the practice in 2300 B.C., but it is generally believed that activity of gambling, in some way or another, has been seen in almost every society in history. From the Ancient Greeks and Romans to Napoleon’s France and Elizabethan England, much of history is filled with stories of entertainment based on the games of chance.

In American history, early casinos were originally known as saloons. The creation and importance of saloons was greatly influenced by four major cities; New Orleans, St. Louis, Chicago and San Francisco. It was in the saloons that travelers could find people to talk to, drink with, and often gamble with. During the early 20th century in America, gambling became outlawed and banned by state legislation and social reformers of the time. However, in 1931, gambling was legalized throughout the state of Nevada, and Las Vegas, presently known as “Sin City”, spawned America’s first official casinos. Soon after, in the state of New Jersey, Atlantic City joined the Casino industry in 1978 to become America’s second largest gambling city.
Games usually have mathematically-determined odds that ensure the house retains a long term advantage over the players. This advantage is called the house edge. In games such as poker where players play against each other, the house takes a commission called the rake. Casinos often give out free items, known as comps to people who are gambling. Often, in most casinos, the more money a player uses the more benefits or comps the player get.

Over the years, casino gambling has evolved and developed, producing a wide range of varied games. Games that are available in casinos are generally known as casino games. A casino game may be defined as a pursuit or activity in which one may gamble cash money or property on possible choices and probable outcomes. Today there is a vast choice of different casino games available. The thrill of games of chance, and the allure of huge jackpots, draws millions every month to gambling meccas like Atlantic City, Las Vegas and Monte Carlo.

Casino games may be divided into three main categories: table games, gaming machines and random number games. Table games offer entertainment which includes the use of cards or dice, such as Blackjack or Poker. Gaming machines, often featured in the form of slot machines, can be played by one player at a time, without the presence of a third party (particularly a casino staff such as a dealer). Random number games feature the choice of different numbers, such as in the games of Roulette or Keno. Source : wikipedia.org