Online casinos usually come in two forms – Downloadable and Instant Play. Downloadable casinos look better and offer more games, but they run on software that has to be downloaded and installed on the player’s computer. Instant Play online casinos offer fewer games and sometimes lower-quality graphics, but can be played instantly on any computer with internet access.
There are several different companies that currently write software used by internet casinos. The biggest ones are Microgaming, Playtech, and Cryptologic, and runners-up include Vegas Technologies, Real Time Gaming, Rival Gaming, NetEnt, WagerWorks and a few others.
All online casinos offer bonuses, promotions, and comps to attract customers and to promote player retention. These include deposit matches, loyalty programs, cash prizes, sweepstakes, tournaments, VIP Clubs, and more. These bonuses often come with conditions attached, which should always be read carefully.
Playing at virtual casinos on the internet for real money requires a deposit to be made – this happens electronically, either with a credit card or through an online banking service. The money won at internet casinos is also real money, and can "cashed out" just like chips at a casino.
Overall, online casinos offer all the thrills and possibilities that old-style brick-and-mortar casinos offer, without the hassle of having to get up and go outside. Online gambling can be very profitable, but only if a player is smart with their money, and knows how to stop when they are ahead.