A Excel sheet can be saved in several formats, but take note, if you save it in the text format, then all formatting shall be lost.
DBF 3, DBF 4
ddBase III and IV. You can open these file formats with Excel, but you can not save an Excel file in dBase format.
OpenDocument workbook. You can save Excel 2010 files so they can be opened in spreadsheet applications using the OpenDocument formats, such as Google Docs and OpenOffice.org Calc. You can also open spreadsheets in th.ods format under Excel 2010. Formatting may be lost when saving and opening files in the .ods.
Portable Document Format (PDF). This file format preserves document formatting and enables file sharing. When the PDF file is viewed online or printed, it retains the default formatting. The PDF format is also useful for documents that are to be reproduced by using professional printing methods.
XPS (XML Paper Specification). This file format preserves document formatting and enables file sharing. The XPS format ensures that when the file is viewed online or printed, it retains the desired format.