XLS Files Explained

Computer files are labeled with a dot followed usually by three to four letters. For example, the .xls extension is a name that refers to a specific program and how it was formatted. In this example, the .xls extension is assigned to spreadsheets that were created in select versions of Microsoft Excel prior to 2007. In ’07, Microsoft released new Excel versions, which were given the .xlsx extension as opposed to the traditional .xls.

Within the Excel document, you can calculate, use graphing tools and pivot tables, and Excel is regarded as the spreadsheet industry standard with a wide range of applications. In 2002 the Excel sheet that was released was a very basic XML-based format and its original intention was that the file extension be .xml. However the Excel program correctly handled the XML files very well, and as a result, .xls began being used by third parties for “export to Excel” applications and capabilities, without having to go through the process of implementing a binary file format.

Due to the engineering of the Excel program, there are a lot of multiuse options that other spreadsheets don’t offer. For example, you can change the color of sheet name tabs, delete all formatting with just a click, filter unique items from any list, add multiple cells together, all along with keystroke shortcuts.

It should also be noted that Excel files use a proprietary format, known as the Binary Interchange File Format (BIFF), and the files are stored in fixed-sized streams. The streams have the vital information about the spreadsheet, like author name, subject, and sheet names.