Files with CSV (Comma Separated Values) extension represent plain text files that contain records of data with comma separated values. Each line in a CSV file is a new record from the set of records contained in the file. Such files are generated when data transfer is intended from one storage system to another. Since all applications can recognize records separated by comma, import of such data files to database is done very conveniently.
Files with ODS extension stand for OpenDocument Spreadsheet Document format that is editable by the user. Data is stored inside the ODF file into rows and columns. It is an 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.
You can also convert CSV into many other file formats. Please see the complete list below.