XLS is the most popular and common format for creating and editing spreadsheets. It takes its name from Microsoft Excel Spreadsheet, is created using the Microsoft Excel system utility. Document data is stored in certain table cells that have their own address. In cells of XLS files, not only fixed data can be located, but also formulas that allow you to relate the content of information in different cells. Like text formats, XLS makes it possible to format the contents of cells - font, font style, color, text alignment. Files of this format can also be launched using Google Drive.
XLSX is a more modern version of the spreadsheet format, a type of e-book within the Microsoft Office Excel suite. It takes its name from the Microsoft Excel Open XML Document. This format has replaced the XLS. Initially included in the paid package of MS Office, but then the Open XML standard was recognized as public. As in XLS, the data is placed in the cells of the table, however, it uses data compression like ZIP. This reduces file size and increases the potential for data security. Data can be entered into the cells manually, as well as by automatic calculations - when special formulas are entered into the cells, starting with the equal sign.