(You can switch between the header and footer by using the Go To Footer tool and the Go To Header tool.) This ensures that the final section in the document has the same header and footer as the section just before it.
Other issues of WordTips detail how you can insert section breaks and apply section formatting. Of the three, section formatting is often the most confusing formatting for people to understand. Word allows you to format your documents on three general levels: sections, paragraphs, and characters.