Drag & Drop features improve the usability of applications. By dragging an item from a list of items (supermarket shelves?) and dropping it into another list or object (shopping cart? ) the user shows the application his intention (to buy the item, for example). The application can then react to that intention, and this enables a fast interaction between user and application.
Generated applications support drag & drop, as does GeneXus IDE. The first allows your application's users to drag & drop objects. Users can, for example, drag a product from a product list and drop it into the invoice's grid. Or drag & drop them into a shopping cart. Or drag any item from any other place and drop it into a different place. The second allows you to Drag & Drop easily inside the GeneXus IDE, dragging & dropping attributes into the Webform, for example, or SDTs into a Data Provider.
IDE drag and drop support
Developing Drag and Drop in Web Panels
Developing Drag and Drop in Panels