The operation is typically used to undo a pivot operation so the data can be re-pivoted by a different column. You would normally select all of the data columns when unpivoting.
Title for Column of Names – enter a name for the new column that will hold the original column names.
Title for Column of Cell Values – enter a name for the new column that will hold the values from the cells in the original table.
Select Columns to Unpivot – select all of the data columns to be unpivoted by position (column letter) or By Name. For every non-blank cell, a row will be created with the original column name and original cell value.
ZZZ (Last Column) – if the data may change over time, with a different number of original columns, select the special column ZZZ (Last Column) in the list. That will include any extra columns to the right of those already selected, should they appear in the future.