What file type should be selected to save an Excel workbook as a template?

Saving an Excel workbook as a template requires the use of a specific file type that preserves the formatting and structure intended for future use. The .xltx file type is designed for saving templates in Excel. When you save a workbook as a .xltx file, it allows you to create a workbook based on that template without overwriting the original template itself, facilitating consistent design and functionality for future projects.

In contrast, the .xlsx file type is used for standard Excel workbooks that contain data, formulas, and other elements. It is not intended for templates. The .xlsm type is similar but includes macros, which are not necessary for a simple template. Finally, the .csv file type is primarily used for structured data storage in a plain text format, which cannot maintain complex formatting or features typical in Excel workbooks, making it unsuitable for saving templates. Thus, .xltx is the appropriate choice for this purpose.