Web Dynpro (WD) is a proprietary web application user interface technology developed by SAP AGand exists in a Java (Web Dynpro for Java, WDJ or WD4J) and an ABAP (Web Dynpro ABAP, WDA) flavor. Both have in general the same functionality, but usually one flavor is improved after the other, so temporary one flavor is more advanced than the other.
Hence, the decision for one of the two flavors shall be based on organizational and business circumstances, but not on functionality. WD follows an adapted MVC pattern and a model driven development approach (“minimize coding, maximize design”) with a large number of dedicated hooks in generated code to place custom coding.
It is intended for business applications that shall follow standardized UI principles, connect to backend systems and be scalable.