Online casino is a derivation of the land-based traditional casino, also known as virtual casinos or gambling sites and providing diverse games or a single one depending on the website operation, franchise, etc. The online casino offers generally better odds than land-based casinos for games such as slot machines where the chances of winning are regulated by the house, the so-called house advantage.

On August 18, 1995 the world's first online casino debuted, Internet Casinos, Inc. (ICI) operating with 18 different casino games and for the first time offering also online access to the National Indian Lottery. However, since the early days ICI operates out of the Turks and Caicos Islands, outside the United States to avoid government prosecution.

Also, in the mid 90's, two other online casinos made their debut claiming to be the first; The Gaming Club and Intertops casino and sports book, which in fact launched the first online sports book before Internet Casinos, Inc.. Building a reputable service with reliable payouts, high security, efficient customer support, and serving a large number of customers excited with this new gambling modality, the online casino succeeded.

The spring of 1996 brought into the gambling scene a second sports book planning to launch an online casino as they did. The Interactive Gaming & Communications Corp. (SBET), soon becoming a publicly traded company listed on NASDAQ. The financial success of this online casino is not only the internet, but also the acceptance of bettors' sports wagers via telephone calls to Antigua on a toll free line via satellite.

Due the American gambling laws of regulations, the online casino industry has been developed mainly from the Caribbean Islands nations, as well as from Asian and European countries where even governments have also entered the business holding their own gambling sites, like Liechtenstein's government operating an online international lottery, not only in German but in six different languages to drive international traffic.

Atlantis, was the first online casino based in Great Britain and licensed by the Isle of Man, an inspirational fact that made Sol Kerzner, its owner, develop a new concept in online gambling; the thematic online casino.

Today, this online casino has become one of a kind offering from five-figure slots payouts and progressives, offering free trips to Atlantis, the Paradise Island in Bahamas, and property of Mr. Kerzner. Atlantis was also the first casino recognizing the importance of players introducing the VIP program, exclusive for London Clubs Members.

According to Rolling Good Times Online, a popular gambling magazine, currently there are 452 gambling-related sites on the internet with thousands of subsidiaries, affiliates, franchises and co-branded sites, and the overall market for online gambling is estimated at approximately $49 billion worldwide on average.