In addition to password protection for your files, Excel offers several features that you can use to protect your work—workbooks, workbook structures, individual cells, graphic objects, charts, scenarios, windows, and more—from access or modification by others. You can also choose to allow specific editing actions on protected worksheets.
For information about additional security issues in Excel, see Chapter 4.
By default, Excel locks (protects) all cells and charts, but the protection is unavailable until you activate it. Click the Review tab on the ribbon and click Protect Sheet to access the Protect Sheet dialog box shown ...