: A workbook is the entire file, while "sheets" are the individual tabs within it. By default, your "Book1" will likely start with one sheet titled "Sheet1".
"Book1.xlsx" is the default temporary name Microsoft Excel assigns to a brand-new, unsaved workbook. Since this is a blank slate, 1. Getting Started with Your Workbook Book1.xlsx
: Use Ctrl + F to find data or F2 to quickly edit a cell's content. : A workbook is the entire file, while