Concepts of Web Dynpro for Java 
This section provides basic background information for application developers, both about the concepts of Web Dynpro for Java and the procedures for designing applications.
The Model View Controller Paradigm
provides an introduction to the model view controller paradigm and describes how it is implemented in Web Dynpro for Java.
See The Model View Controller Paradigm
The Component Concept
represents a building block for creating complex business solutions. This section focuses on the componentization within a DC project or a local Web Dynpro project.
Designing Web Dynpro Applications
gives an overview of the architecture and detail design of Web Dynpro applications.
See 
Designing Web Dynpro
Applications
The Request/Response Cycle
of a Web Dynpro application is described in Web Dynpro Phase Model