Each grid row in DataGrid for WPF can be expanded to display a row details section. This row details section can display more details information about a specific row's content. The row details section is defined by a DataTemplate, RowDetailsTemplate that specifies the appearance of the section and the data to be displayed. For an example, see the RowDetailsTemplate topic.
Using the RowDetailsVisibilityMode property the row details section can be displayed for selected rows, displayed for all rows, or it can be collapsed. See Setting Row Details Visibility for more information.