Excel 2003:
.xls = Workbook
.xla = VBA Add-in
.xlb = Toolbar (where custom toolbar settings are stored)
.xlc = Chart
.xld = Dialog (from older versions of Excel)
.xlk = Archive (Excel spreadsheet backup)
.xll = DLL Add-in
.xlm = Macro
.xlt = Template
.xlv = VBA Module
.xlw = Workspace (collection of multiple Workbooks)
Excel 2007 and Excel 2010:
.xlsx = Workbook (XML format)
.xlsm = Macro-enabled Workbook
.xlsb = Excel Binary Workbook (instead of XML format)
.xltm = Macro-enabled Template
.xlam = Add-in (XML format)
.xls or .xlsx depending which version of the software you are using.
The extension for excel is .xls
file extension
* The file extension of a Word document is .doc * The file extension of an Excel speadsheet is .xls
the normal extension for Excel is xls if pre 2007 otherwise xlsx
For a standard Excel document, prior to Excel 2007, it is xls and xlsx is used in 2007. There are other kinds of files created by Excel, like templates which can be xlt or macros which can be xlm and xla for Add-ins, and there are other extenions. For 2007, you add x to the end of them.
A file that has .xls, .xlsx, .xlsm as file extension then it is known as excel file.
the .xls
file extension
xlsx
.XLS files are standard Microsoft Excel spreadsheet files. .XLT extension is used for the Excel template files. - Neeraj Sharma
Normally xls is the extension for an Excel spreadsheet document.
xlsx is the main extension used for Excel 2007.