Every time you start Excel, by default, Excel will create a new blank workbook named "Book 1". You can see the workbook name in the title bar of the Excel program interface. The relationship between a workbook and a worksheet is just like the relationship between a book and a page. Each workbook can contain multiple worksheets, and the maximum number of worksheets a workbook can contain is limited by memory. By default, each new workbook contains three worksheets, and the worksheet labels can be seen at the bottom of the Excel program interface. The default names are "Sheet 1", "Sheet2" and "Sheet3". The worksheet name is the job label name.