A casino is an establishment for gambling. It is often combined with hotels, restaurants, retail shops, and/or cruise ships. Licensed casinos are regulated by government agencies. Casinos are also known for hosting live entertainment, such as music, comedy shows and sports events.
While gambling likely existed in some form before recorded history (primitive protodice and carved six-sided dice have been found in archaeological sites), the modern casino as an all-in-one entertainment destination did not emerge until the 16th century, during a period of gambling crazes that saw Italian aristocrats gather in special clubs called ridotti to gamble and socialize. 
Today, casinos are designed around noise, light and excitement, offering a variety of games with built in advantages for the house, such as slot machines, blackjack, roulette and craps. These “house edges” may be small, less than two percent, but they accumulate through the millions of bets placed each year and earn the casino billions in profits.
Casino security personnel watch over the players to catch any blatant cheating, and table managers and pit bosses watch for betting patterns that might signal cheating or collusion. Technology has also increased the level of surveillance at casinos, with each table or slot machine wired to a central computer to oversee exact bets minute by minute and quickly detect any statistical deviation. Some casinos also have electronic systems for dealing cards or observing the spin of the roulette wheel to detect any manipulation.