XLS vs. XLSX
The current default file extension for an Excel file is XLSX.
Prior to Excel 2007, the default file extension was XLS.
Determine if a file contains macros before you open it.
Macros contain code that could damage files and compromise computer security if they come from untrusted sources.
Excel files containing VBA and XLM macros use the XLSM extension.
XML and HTML
XML stands for extensible markup language.
XML is related to HTML, the extension used for web pages.
Template files are used as starter files for new workbooks.
The difference between the two extensions is that the XLTM format can store VBA and XMLmacro code.
Excel files created in one operating system can be opened the other.
One exception to this is Excel 2008 for the Mac, which does not support VBA macros.
In the dialog box, accept the suggested file name or pop in a new name for theworkbook.
In theSave as typeorFile Formatlist, choose the format for the resulting file.
SelectSaveto save the file in the new format and return to the current worksheet.
