These lines are sometimes called horizontal rules and come in a number of different variations. Word lets you add simple lines, double lines, dotted lines, and jagged lines, for example.

There's not one, but two easy ways to insert a horizontal line into a Word document.

Whether you want to use page numbers to distinguish between a novel's preface and main body, a dissertation's introduction and chapters, or a textbook's content and index, using Microsoft Word's ...