There is a difference between copying all the cells in a sheet and copying the sheet.
To copy and paste all cells in a sheet:
1. Select the cells in the sheet by pressing Ctrl+A (in Excel 2003, select a cell in a blank area before pressing Ctrl+A, or from a selected cell in a Current Region/List range, press Ctrl+A+A).
Click Select All at the top-left intersection of rows and columns.
2. Press Ctrl+C.
3. Press Ctrl+Page Down to select another sheet, then select cell A1.
4. Press Enter.
To copy the entire sheet:
Copying the entire sheet means copying the cells, the page setup parameters, and the defined range Names.
1. Move the mouse pointer to a sheet tab.
2. Press Ctrl, and hold the mouse to drag the sheet to a different location.
3. Release the mouse button and the Ctrl key.
1. Right-click the appropriate sheet tab.
2. From the shortcut menu, select Move or Copy. The Move or Copy dialog box enables one to copy the sheet either to a different location in the current workbook or to a different workbook. Be sure to mark the Create a copy checkbox.
1. From the Window menu, select Arrange.
2. Select Tiled to tile all open workbooks in the window.
3. Use Option 1 (dragging the sheet while pressing Ctrl) to copy or move a sheet.
Moving a sheet from a workbook with defined range Names or linked formulas will create links in the new workbook
Screenshot // Copying or Moving a Sheet