IIA System Architectures

Web architectures are very simple, and Web systems are easy to deploy and maintain.  The Web browser communicates only with Web servers, a page at a time.  Each Web server communicates with an application server, which provides the business logic, accessing other resources as needed:

There are two main IIA architectures: server-integrated and client-integrated.

In an IIA server-integrated system, the presentation layer is distributed between the originating application server and the client, as shown below.  Application code running on the client is closely coupled with application, and all data sent to the client flows through the server, retaining the tight integration with the application server that characterizes Web applications today:

In an IIA client-integrated system, the presentation layer is loaded entirely into the client execution environment, often along with some of the business logic, as shown below, resulting in a loose coupling between the client and server-resident resources or application components: