The PivotGridControl's data (and nested values in groups) are sorted by fields in the Column Header Area and Row Header Area. The default sort order is ascending.
To change a field’s sort order, specify the PivotGridFieldBase.SortOrder property or click the pivot grid field's header.
In the picture below, the data rows are sorted alphabetically in ascending order by the Product Name field. The data columns are sorted in ascending order by the Order Date field.

The sort mode determines the attribute by which to sort field values. You can use the PivotGridFieldBase.SortMode property to specify the sort mode for each field.
When a pivot grid obtains its data from a non-OLAP data source, you can sort field values by the value itself (default mode), by the field's displayed text, or implement a custom sorting algorithm as shown in the following table:
When a pivot grid obtains its data from an OLAP Data Source, you can sort field values by the value itself (default mode) or by the field's display text. the following OLAP-specific modes are also in effect: