In Microsoft Office Word and Microsoft Office Excel, you can split the screen to see two separate parts of a document at once.
On the View tab, in the Window section, click Split, and then click the screen where you want the split to appear. You can then navigate parts of the document separately in each window.

Excel adds both a horizontal and a vertical split to the screen. If you don't want one of them, drag the line up to the top or the left side and drop it at the edge of the screen, where it will disappear.

To return to the single-screen view of the document in either Word or Excel, go back to the Window section and click Remove Split.