You can split the Word window into two panes so that you can view two different parts of a document at the same time. This is useful, for example, if you need to refer to one part of the document while working in another.
On the View tab, click Arrange, and then click Split.
If the window is wide enough, Word displays Split directly on the View tab.
To adjust the relative sizes of the panes, move the mouse pointer to the dividing line, and when you see the split pointer, click and drag the dividing line to a new position.
Note: To remove the split in the window, drag the dividing line to the top or bottom edge of the window.
Tip: In addition to simultaneously viewing two different parts of the same document, you can also use the split window to display two different layouts, such as Print Layout and Outline. After creating the split, click in the pane that you want to change, and then select a different layout on the View tab.