Working with Multiple Worksheets
A workbook is a multi-page Excel document that contains multiple worksheets. Sometimes you will want to work with the worksheets one at a time as if each is a single unit. Other times, the same information or formatting may need to be added to every worksheet. You can type and retype the same information in each worksheet and apply identical formatting, or you can group the worksheet and enter the information just once.
Worksheets can also be combined into a group. Grouping worksheets allows you to apply identical formulas and/or formatting across all worksheets in a group. When you group worksheets, any changes made to one worksheet will be changed in any other worksheets in the group. If several worksheets will have the same data—regions, departments, quarters, months, weeks, and days, for example—then you type it once and it will appear on every worksheet included in the grouping.
When you're finished entering, moving, copying, or formatting data, you'll need to ungroup worksheets. If you do not ungroup the sheets, any work you do in one sheet will be duplicated in all of the others.