Function

• File types with the extension .xlsx are used by Microsoft Excel for workbooks or spreadsheet documents. .Xlsx replaces the older .xls file extension, formerly used by Microsoft Excel 97 to 2003.
  
  

History

• The newer file extension utilizes Open XML technology and combines it with zip compression. This union produces smaller files and other benefits.
  
  

Other Benefits

• Not only are the files smaller, but adopting the open format allowed IT professionals more cross-platform compatibility. This is a step away from other Microsoft products, which are not readable by other applications, browsers or platforms.