Previewing a worksheet before final printing is recommended. That way, one can see how the worksheet will look like once it is printed. Layout features and special header/footers can all be seen in the preview mode.

To preview the worksheet, click on File in the menu bar and select Preview.

In the Preview mode, a window will appear with an image of the spreadsheet. There are several things you can do here. Look at the graphic below to see what these are in the Preview mode.