Add Pivot lets you generate a pivot attached to the right side of the tabular report. This pivot is always on the right side of the fields tab – nothing is further to the right of the pivot. You may add one and only one pivot on the fields tab, meaning that you may have one and only one pivot per report.
The first thing you must do is select the pivot columns. Values in this field will be used to generate the main columns in your pivot. You can thing of this as rotating an entire field 90 degrees, from vertical to horizontal.