Excel Files Types

By Author: Ed Bolton
Total Articles: 17
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Excel is Microsoft Office's in-built spreadsheet package. Over the past 20 years, Office has become so ubiquitous that their ".xls" file format has almost become a byword for a spreadsheet. Just as Word documents are saved as ".doc", so Excel files are saved as ".xls"



Except that hasn’t been the case since the release of Office 2007. The default file type in Excel is now ".xlsx". This is because Microsoft changed the underlying architecture of their sheets and you may notice large files are a little smaller once converted to the new file type.



Although ".xlsx" is the standard default file setting, more recent versions of Excel also offer you the ".xlsm" format. The "m" at the end indicates the presence of macros. Macros are scripts that allow Excel gurus to program their own spreadsheets. If you receive an ".xlsm" file from an Excel beginner, it is unlikely they wrote the code themselves, so it is important that you trust the file’s original creator. That’s because macros can be used to delete important system files and download viruses.



So by introducing ...
... a second standard file type, Microsoft has provided an advance warning that a file contains Visual Basic scripts. Of course, there are still a lot of older ".xls" files in existence but if you have a spreadsheet in everyday use, it should be one of those three formats.



Of course, you may wish to import data into Excel. Often this would come from another database and be stored in a text based format, the most common being the ".csv" file. "Csv" means comma-separated values. That is to say that a comma marks the end of each cell of data, and each new line is a new row. The key point is that the file will not have any formatting and will only consist of a single sheet. At least it is laid out like a spreadsheet.



You can open regular text (".txt") files that have nominally been laid out as a set of data, but each entry may be distinguished by some other character, or a tab. Excel will ask you how the data is separated upon opening. Occasionally you will want to open data that is not in spreadsheet form at all e.g. a list of names, but that you could manipulate into a meaningful form using a combination of macros and formulas. That may require the guidance of an Excel support team.



Other formats tend to be workplace specific e.g. the ".xml" format can be extremely useful, but only if you have other applications that use it. There is one exception. That is the Excel add-in. The add-in was formerly the ".xla" format but it has now been extended to ".xlam". An add-in is simply some pre-written code that allows you to perform a required operation at the click of a button. You will notice an "m" has been added to the end of the file extension to indicate the inclusion of code.



Add-ins differ from macros because a macro is stored in a specific spreadsheet, whereas add-ins can be instructed to auto-load whenever you open Excel. That means an add-in is always available and the code can be accessed from any files. They are most useful if you are attempting to perform a common task for which Excel has no built-in function e.g. if you need to remove duplicates from lists.



The only list longer than the number of file types you can open in Excel, is the number of formats into which you can save your spreadsheet. This is to ensure your work is compatible with any other feasible database or software.



About the Author: Ed Bolton is the founder of Excel4Business, and provider of Excel support.