When working on a big Word document, sometimes it’s necessary to reference something earlier in the document as you create content several pages down. You can use two methods.
On the View tab in the Windows group, click the Split button. This holds one portion in place as you scroll to the area you need to reference in the other portion. You can also use the New Window button and Arrange All to see both Windows at the same time on the same document. In this case, each Window on the document will have its own ribbon.