The workbook is the file that contains all of the elements of your Excel spreadsheet. Don't confuse a workbook with a worksheet in Excel-the worksheet is an element of a workbook.

The foundation of Excel is a workbook. Each Excel workbook is a separate document, within which you create one or several worksheets.

Applying the same formatting to each sheet in an Excel workbook is ideal when each of your sheets is set up the same, but it can be helpful in other circumstances as well.