XLSXMicrosoft Excel Open XML Spreadsheet
XLSX is well-known format for Microsoft Excel documents that was introduced by Microsoft with the release of Microsoft Office 2007. Based on structure organized according to the Open Packaging Conventions as outlined in Part 2 of the OOXML standard ECMA-376, the new format is a zip package that contains a number of XML files. The underlying structure and files can be examined by simply unzipping the .xlsx file.
ODSOpen Document Spreadsheet
Files with ODS extension stand for OpenDocument Spreadsheet Document format that are editable by user. Data is stored inside ODF file into rows and columns. It is XML-based format and is one of the several subtypes in the Open Document Formats (ODF) family. The format is specified as part of the ODF 1.2 specifications published and maintained by OASIS.