This section is for first-time adopters and for maintainers returning to TreeDataGrid after the API surface has grown. It explains what the package ships, how the flat and hierarchical source models differ, and which guides to read after the first grid renders successfully.
Continue with Concepts if you want the mental model for rows, cells, indexing, and selection.
Continue with Guides if you want scenario-driven recipes for editing, sorting, styling, and events.
Continue with XAML Usage if you need theme resources, templates, and customization hooks.