This document explains how to create Z cells in a report using the Report Painter tool in SAP. Z cells allow formulas to be defined for specific cells in a report. The steps shown include creating a sample report with rows and columns, selecting cells to define as Z cells, and entering formulas for those cells to calculate values like column totals and year-over-year changes. Defining Z cells provides a way to dynamically calculate and display different values within the same column of a report.