Online casino is a derivation of the land-based traditional casino, also known as virtual casinos or gambling sites and providing diverse games or possibly a single one depending on the website operation, franchise, etc. The on-line casino offers generally better odds than land-based casinos for games such as slot machines where the probability of winning are regulated through 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 very first time offering also online access to the nation's Indian official lottery. On the contrary, considering that the early days ICI operates out of the Turks and Caicos Islands, outside the states to avoid government prosecution.