An online casino is the online version of a traditional casino. It is a venue for a gambler to play a casino game via the Internet. It is also called a virtual casino or an Internet casino. The first online casino, Internet Casinos, Inc. (ICI), made its debut on 18 August 1995 with 18 different casino games. Two other online casino venues, namely The Gaming Club and Intertops casino and sportsbook, emerged in the mid-90s.

A typical online casino offers games such as blackjack, poker, roulette, slot machines, or baccarat. It operates through a website, casino software which is usually purchased from reputable companies such as Microgaming or Realtime Gaming, and a server. A random number generator or RNG is also used to ensure the random appearance of certain numbers, cards, and dice during a game.

If a player wants to improve his or her skills prior to playing for real money, an online casino can give that option through its virtual play. And once a player decides to gamble with real money, an online casino can give this player a chance to win bonus prizes or gifts. In addition, studies show that gamblers playing in online casino are more likely to win more as compared to playing in real casinos.

To start an online casino business means investing at least $1.5 million, but only a few employees are needed, unlike setting up land-based casinos which can take up to $300 million and require more employees. The current annual revenue of an online casino is approximately $18 billion.