The first checkbox enables sorting at the table/grid level (this acts as a primary/required check). After this is checked all the columns will be sortable.

Now other check is at each column level where you can turn off the sorting for a particular column. Let say you are displaying image as one of the columns, so you don't want to give sorting abilities to users for this column, the second setting overrides the behavior for this column.

Let us know if this helps :)

Hi,

Select "Allow Column Sorting" checkbox to allow users to sort the rows on a column in the grid. This setting applies to all columns.

You can disable sorting for individual columns by clearing the Enable Sorting check box in a column's Cell Properties panel.