A group is the abstract structuring concept for an application. Groups can be nested which allows them to form a hierarchy that defines the structure of a user interface. Each group can also contain UI elements such as inputs and outputs as well as types. To make this more tangible, groups could be used to model the following implementation concepts:
- HTML forms, pages, containers, and sections
- mobile application screens, pages, forms and containers
- accordions (vertically stacked list of items with show/hide functionality)
A UI designer is free to arrange the contained elements in any fashion, but presumably in a way that is consistent with their overall UI design theme.