Online casinos come in three basic types: casino software downloads, Flash- or Java-based online casinos, and HTML-based casinos. Each of these types has their own strengths and weaknesses and your decision to go with one type or another should be based on your computer configuration and the quality of your Internet connection, as well as your personal preference.
Most online gamblers prefer Casino software downloads because of the superior graphics and fast game play offered by these types of online casinos. The main disadvantage with this type of casino is that you need to install the software in your computer and therefore can only play from that particular machine.
Flash- or Java-based casinos are the second most popular choice of online casino. Since you do not need to download any software, they will work from any computer and you can get started playing quickly. The graphics and sound quality offered is generally pretty good, although not at the same level as the download casinos.
HTML-based online casinos are not as popular as the two previous types since they offer fairly limited graphics and sounds. Some people do prefer them however since the game play is usually quite fast and very simple owing to the absence of heavy graphics.