A web application is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is hosted in a browser-controlled environment (e.g. a Java applet) or coded in a browser-supported language (such as JavaScript, combined with a browser-rendered markup language like HTML) and reliant on a common web browser to render the application executable.
Web applications are popular due to the ubiquity of web browsers, and the convenience of using a web browser as a client, sometimes called a thin client. The ability to update and maintain web applications without distributing and installing software on potentially thousands of client computers is a key reason for their popularity, as is the inherent support for cross-platform compatibility. Common web applications include webmail, online retail sales, online auctions, wikis and many other functions.
Interactivity in websites is being adopted at a furious pace. In this light, the knowledge and practice of Rich Internet Applications (RIA) has become indispensable for website designers. 
Many web designers creates ‘top of the line’ Rich Internet Web 2.0 Applications using RIA technologies such as Macromedia Flex, AJAX with PHP and Ruby on Rails Framework, Macromedia flash/FLEX and XML (AJAX). These Rich Internet Applications (RIA) solutions are Web based applications that have the features of traditional desktop applications based applications with better interactivity and data communication.
RIAs have become the de-facto technology choice to simplify complex processes like registration, online shopping and data analysis. RIAs can be effectively used to provide an engaging and interactive experience to customers or managers. RIAs can also be made to work with existing web application infrastructure and small modules and can be deployed even as part of normal HTML pages.
Rich Internet Applications combine cutting edge technology with innovative business processes to provide cost-effective business solutions for small and mid-sized businesses, large corporate enterprises, and government entities. Source : Wikipedia
If you require any web based development solutions, feel free to contact us for consultation before you engage your application solutions provider.
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