XLS File Format
XLS, .xls file is the file extension of spreedsheet application Microsoft Excel, which is developed by Microsoft. XLS files can be run on both Microsoft Windows and Mac OS X platform. .xls document is the most popular tool for creating and formatting spreadsheets. Microsoft Excel up until 2007 version used a proprietary binary file format called Excel Binary File Format (.XLS) as its primary format. XLSX/XLSM files can be opened in Excel 2007 or later.
.xls files features stores data in a table with rows and columns, answer statistical, engineering and financial needs, set password for protecting Excel data, table cells may contain manually entered data or the results computed from the data of other cells, often used to create charts and graph,etc. You can open, view or edit .xls, .xlsx, .xlsm files can be open with Microsoft Excel, Openoffice.org, Microsoft Excel Viewer, Kingsoft Spreed, etc on Windows, Mac, Linux and Android.