About Spreadsheet File Formats
A spreadsheet file contains data in the form of rows and columns. A spreadsheet file can be saved in several different file formats, each having a different file extension for unique representation. Data is stored in cells either in plain form such as text string, numbers, date, currency, etc. or as formulas that change a cell’s value when referenced cell values change.
Common spreadsheet file extensions and their file formats include XLSX (Microsoft Excel Open XML Spreadsheet), ODS (OpenDocument Spreadsheet) and XLS (Microsoft Excel Binary File Format).