Identical worksheets are needed prior to using the Consolidation feature, creating a sum across worksheets or using the Paste Special Math features to create summary worksheets. By grouping the worksheets first and then adding rows or columns, changing headings and other formatting operations, you ensure that the spreadsheets remain uniform.
How does Excel store Worksheets? Worksheets are saved in an Excel file called a workbook. These workbooks are what Excel uses to collectively organize all the different related parts of many different related worksheets as well as the related charts, graphs and various other objects within Excel.