You may have a sheet or sheets in your workbook that contains confidential information or information that you do not update that often. You can hide these sheets fro view as follows -
1. The sheet you want to hide should be the active sheet.
2. Click on Format -> Sheet -> Hide. The sheet will be hidden.
(For Excel 2002, right click the sheet tab and select Hide).
To unhide the hidden sheet, click on Format->Sheet -> Unhide. Select the sheet and click Ok.
For versions later than 2003, right click on the sheet and select hide/unhide.