XLSBMicrosoft Excel Binary Spreadsheet File
XLSB file format specifies the Excel Binary File Format, which is a collection of records and structures that specify Excel workbook content. The content can include unstructured or semi-structured tables of numbers, text, or both numbers and text, formulas, external data connections, charts and images. Unlike XLSX (which is based on Open XML file format), the XLSB represents binary Excel workbook file.
XLSMicrosoft Excel Binary File Format
Files with XLS extension represent Excel Binary File Format. Such files can be created by Microsoft Excel as well as other similar spreadsheet programs such as OpenOffice Calc or Apple Numbers. File saved by Excel are known as Workbook where each workbook can have one or more worksheets. Data is stored and displayed to users in table format in worksheet and can span numeric values, text data, formulas, external data connections, images and charts.