Rich Internet Applications (RIA) is a completely new kind of web experience that offers the flexibility of an intelligent desktop application. It combines the vital strengths of both web-based and desktop applications. It provides the facility to transfer the processing necessary for the user interface to the web client. 

Rich Internet Application can be built by using the following technologies:

AJAX: In AJAX the client and server interaction is asynchronous in other words the client server interaction is not based on requests. Making the best use of this technology, the server can upload data to the browser without waiting for a request. The best part of this technology is that rich internet applications built on AJAX are fast and easy to download.

Flash: In this case rich internet applications are built on Flash, where a flash player is used to render flash content to users. It is mostly used in RIA to integrate audio and video content. This technology is ideally suited for rich internet applications where the emphasis on animations and graphics is high.

Some of the major advantages of Rich Internet Applications are:

• It provides an enhanced and interactive browsing experience to the users. In rich internet applications most of the processing takes place at the client's end thereby reducing the server load and bandwidth consumption.
• It has a modular architecture and thus enables various components to be reused and integrated with a variety of solutions.
• It also helps in developing responsive applications that can be used to simplify complex processes within applications. Processes involving multiple steps can be combined into a single screen with different tabs for each process thereby enabling the user to collectively save the details of all the steps.
• It also helps in reducing the network traffic significantly. A rich internet application-specific client engine can be more intelligent than a standard Web browser when it comes to decide what data needs to be exchanged with servers. This can speed up individual requests or responses because less data is being transferred for each interaction, and overall network load is reduced.