A rich Internet application performs and functions like a locally installed desktop program, except that it is used through the Internet. Without Internet access, there is no way for a computer to open and use the rich Internet application. Unlike a traditional program that must be installed through a hard drive and added to a desktop, this application takes up no room and does not go through the installation process. At the same time, some applications may only work on certain Internet browsers, or there may need to be programming languages or other supplementary programs installed to open these applications.
Unlike other Internet applications that only have a few features or low power, a rich Internet application is meant to be as powerful as a regular desktop program. This means users, outside of going through the Internet to use the program, should not notice any differences between the functionality of rich Internet programs and desktop programs. There are other similar programs, known as thin-client programs, which are accessed from a server; this is similar to a rich Internet application but, because the server is involved, it is classified differently.
One of the largest differences between a rich Internet application and a desktop application is how they are accessed. A desktop application is launched from a desktop, while an Internet application is accessed through the Internet. This means the computer must have uninterrupted Internet access or the program either will not start or will cease to function when the connection is lost. While this can be a disadvantage for people who have poor Internet strength, it normally makes it easier for people with good Internet connections to use programs.
When someone buys or receives software, it normally must be installed. The installation is rarely long, and some programs only take up nominal hard drive space while others take up a larger space. In most cases, a rich Internet application is not installed; it may need to be downloaded, but even this is uncommon.
At the same time, other programs may need to be installed. Some rich Internet applications cannot properly function without some backup, and these supplementary programs provide that. Unlike desktop applications, in which each program is individually installed, the one supplementary program should be able to support many Internet applications. There also is a chance that the rich Internet application will only work on a certain browser or that some features may work best in a certain browsing environment.