Probably 99% of all Excel workbooks are saved in the XLSX file type these days. But there are various other file extensions available: For example XLSM, XLSB or “older” Excel users might still remember the XLS file type. What are the differences of these file types? And even more important: Which one should you use?
Did you know that Excel files are actually a zipped collection of XML files? You can easily explore and edit the complete structure of your Excel workbook. All you have to do: Rename and unzip the .xlsx file. Let’s take a look at it.