In my previous article, we were discussing the Rich Internet Application architecture. Now we will go a little in-depth about what a Rich Internet Application is.Rich Internet Application ArchitectureFrom the above diagram a quick question will arise in all of our minds.By placing the presentation logic in the client side, how does the presentation and business layer communicate?For that is the WCF RIA Services. WCF RIA ServicesThe main role of a WCF RIA Service is to provide a complete view of an application by having presentation view on one side and the database side on the other end. It generally simplifies the overall development tasks.Domain Service and the Domain Context are the two key things that play a vital role in WCF RIA Services. Domain ServiceIt generally exposes a set of methods required by the presentation layer for querying and returning the set of data. We can simply say it encapsulates the business logic of an application. To define a domain service, you should specify set of operations that are permitted through the domain service. Following methods can be added to a domain service