Types of chat room:

Java Chat rooms: The most common and popular chat scripts are based on java which is object oriented language. Java is freely available and comes with virtually every computer sold today. To use a Java chat room you must have Java enabled in your browser. Java chat rooms load quickly and are reasonably fast to use. However, they require you to keep the new release of Java. You can get them from www.java.com  

Flash Chat rooms Flash chat is an upgraded version of chat rooms that is becoming more and more popular. Flash chat rooms use Adobe/Macromedia Flash Player client that are integrated into a website. Flash Chat rooms require that the Macromedia Flash Player from Adobe be installed on your computer. You can get the flash player for free from www.adobe.com . 

Internet Relay Chat (IRC) IRC is multi-user chat network where people around the world can chat and talk in channels or in private. To use IRC you must install IRC client on your computer. Using this client, you can connect to an IRC server, which is connected to other IRC networks. An IRC may have thousands of people you can chat with. IRC is being used for a long time.