Professional ASP.NET 3.5 AJAX

1.1. Why AJAX Applications Are Needed

Web applications were in a rather stagnant state for many years. The first "Web" applications were nothing more than text and some images, all represented in basic HTML tags. However, this wasn't what people wanted; they wanted more — more interactivity, a more integrated workflow, more responsiveness, and an overall richer experience.

When building applications, even today, you have to make some specific decisions that really end up dictating the capabilities and reach of your application. Probably one of the more important decisions is the choice of building the application as a "thin" client or a "thick" client.

A thick client application is a term used for applications that are either MFC (in the C++ world) or Windows Forms applications. These types of applications also provide the container along with all the container contents and workflows. A thick client application is typically a compiled executable that end users can run in the confines of their own environment, usually without any dependencies elsewhere (for example, from an upstream server).

A thin client application is the term generally used for Web applications. These types of applications are typically viewed in a browser, and your application can provide end user workflows as long as it is contained within this well-known container. A thin client application is one whose processing and rendering are controlled at a single point (the upstream server), and the results of the ...