Online casinos can be divided into three groups based on their interface: web-based casinos, download-based casinos, and more recently live casinos. Some casinos offer multiple interfaces.

Web-based online casinos

Web-based online casinos are websites where users may play casino games without downloading software to the local computer.In these websites 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.

Downloadable online casinos

These downloadable online casinos require the download of the software client in order to play on the casino games offered. The online casino software connects to the casino service provider and handles contact without browser support. Downloadable 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 downloadable online casino client does take time. As with any download from the Internet, the risk of the program containing malware does exist.

The difference between both the online casino("web-based Casino" and "Downloadable online Casino") is the same as the difference between any online game or downloadable computer game.

Live-based casinos

Live-based casino gaming allows web players to interact with games played in a real world casino environment. Online players can see, hear, and interact with live dealers at tables in casino studios worldwide.