Casinos were facilities especially designed for gambling and entertainment. The odds in such establishments were almost always skewed in the favor of the "house". Casino chips were used to represent money.
During the 20th century on Earth, casino's were popular and well established in North America. The state of Nevada was well known for its cities, including Reno and Las Vegas, whose main tourist attraction were their gambling facilities. This was so much the fact that the hotels themselves were casinos. (DS9: "Our Man Bashir", "His Way", et al.)
During the 1950s and 1960s, several period-famous entertainers were often found in hotel/casinos. These individuals include: Joey Bishop; Sammy Davis, Jr., Jimmy Durante, Shecky Greene, Peter Lawford, Dean Martin and Frank Sinatra. (DS9: "His Way", et al.)
By the mid-24th century, the Ferengi were well known for their gambling establishments. They often employed dabo girls, who served as both croupiers and distractions to gamblers. By 2377, they also employed casino ships to mobilize their businesses. (DS9: "Captive Pursuit", "The Abandoned", et al.; VOY: "Inside Man")
In 2372, in the holosuite program Julian Bashir, Secret Agent, Julian Bashir played Mr. Duchamps in a lopsided game of baccarat, which earned him the five million francs he required to meet Dr. Noah. (DS9: "Our Man Bashir")