Web Dynpro is a strategic technology from SAP for the development of web-based applications. It was developed within the scope of the NetWeaver initiative in order to introduce a new standard for user interfaces and provide a stable development platform for the implementation of interactive business processes.
Web Dynpro is based on a model-driven framework, which facilitates the development of components or applications that can be reused and combined in strict adherence to the MVC model. Most importantly, this involves a metadata model for the declarative description of the user interface elements, from which the framework then generates the web application.
By contrast with SAPUI5, Web Dynpro is intended more for complex and performance-intensive desktop applications.