Online casinos, also known as virtual casinos or internet casinos, are online versions of traditional ("brick and mortar") casinos.
Online casinos enable gamblers to play and wager on casino games through the Internet.
Online casinos generally offer odds and payback percentages that are comparable to land-based casinos.
Some online casinos claim higher payback percentages for slot machine games, and some publish payout percentage audits on their websites.
Assuming that the online casino is using an appropriately programmed random number generator, table games like blackjack have an established house edge.
The payout percentage for these games are established by the rules of the game.
Reliability and trust issues are commonplace and often questioned. Many online casinos lease or purchase their software from well-known companies like Microgaming, Casino on net, Playtech, CryptoLogic, Grand Virtual Games, CGTV Games, Skyll on net, Rummy Royal in an attempt to "piggyback" their reputation on the software manufacturer's credibility.
These software companies either use or claim to use random number generators to ensure that the numbers, cards or dice appear randomly.
Online casino types:
Online casinos can be divided into two groups based on their interface: web-based and download-only casinos. Some casinos offer both interfaces.
Some casinos offer 'Live gaming', either exclusively, or as part of a wider online casino offering. In live online casinos, popular casino games such as roulette and blackjack are dealt by real dealers in casino studios, in an attempt to convey more of the atmosphere of a physical casino.
Player actions (including chat) such as 'hit' in the game of blackjack may be transmitted to the dealer; in some online casinos more than one player may 'sit' at a particular 'seat' on the table, and in this case there is no interactivity between player and dealer, the question of which player(s) requested the extra card that the dealer dealt and which chose to 'stand' will be handled by the software.
It is usual for players to be able to observe a video feed of the action, and equally common for players to opt to turn it off, if they lack the bandwidth - as the cards are read by OCR and other technology, the video feed is only ever a visual cue.
Web-based online casinos
Web-based online casinos are websites where users may play casino games without downloading software to the local computer.
Games are mainly represented in the browser plugins Macromedia Flash, Macromedia Shockwave, or Java and require browser support for these plugins. Also, bandwidth is needed since all graphics, sounds and animations are loaded through the web via the plugin.
Some online casinos also allow gameplay through a plain HTML interface.
Download-based online casinos
Download-based online casinos require the download of the software client in order to play and wager on the casino games offered. The online casino software connects to the casino service provider and handles contact without browser support.
Download-based online casinos generally run faster than web-based online casinos since the graphics and sound programs are located within the software client, rather than having to be loaded from the Internet.
On the other hand, the initial download and installation of a download-based online casino client does take time. As with any download from the Internet, the risk of the program containing malware does exist (but it is very rare with the online casino).
Still the graphics and sounds at download-based online casinos are most of the time much better than those at web-based online casinos.
Moreover, in some online casinos game effects in download-based games run more smoothly and much faster than in web-based online casinos (which is noticeable in spinning slots and dealing cards in blackjack).