See the table of contents while editing further down
If you need to check a table of contents at the start of a long report while editing a section much further down, splitting the window lets you view both parts at once without constantly scrolling back and forth.
Split vs. opening a New Window
Split divides a single window into two panes of the same document. Word also offers "New Window" on the View tab, which opens a second, separate window showing the same document -- useful if you want to drag the two views onto different monitors instead of stacking them in one window. Either way, edits in one view appear in the other instantly, since it's the same underlying file.
Frequently Asked Questions
Are the two split panes the same document?
Yes -- splitting just shows one document in two windows. Editing in either pane updates the same document in real time.
How do I remove the split?
Click "Remove Split" on the same View tab, or double-click the divider line, and the window returns to a single pane.