Spreadsheet created with Microsoft Excel, a program used to create spreadsheets; stores data in worksheets, which contain cells arranged in a grid of rows and columns; may also contain charts, mathematical functions, styles, and formatting; commonly used to store financial data and to create simple or complex mathematical models.
Each cell in an XLSX spreadsheet may be formatted individually. For example, cells may have a number, text, currency, or other format as well as color, border style, custom font, and size. Cells may reference other cells to compute a resulting value.
XLSX files are created using the Open XML standard, which was introduced in Microsoft Office 2007. They are stored as a compressed Zip archive, which contains a collection of individual files. The archive includes the file [Content_Types].xml, which describes the spreadsheet, and an XML file for each worksheet within the spreadsheet.
NOTE: XLSX files can be opened in Excel 2007 or later. They are also backwards compatible with earlier versions of Excel via Open XML component support.
Common XLSX Filenames:
Workbook1.xlsx - The default filename Microsoft Excel gives to new workbooks beginning with Excel 2007.