A family of Microsoft word processing software products for creating web, email, and print documents.
The following two links may give you some clarification:
- Header/Footer Settings Recap
- Quick Reference Guide for Headers, Footers and Page Numbers
- Toolkit for Advanced Management of Headers and Footers
Every Section of a Word document has three header parts and three footer parts, whether or not you see them or they have any content. They can be the same or different. By default they are different and they are separate, changing one does not change another. These can be linked between sections. A page can have more than one section in it.
Add in the Header and Footer Building Blocks and things get crazy. When you use these, you replace existing headers or footers, not edit them. The same happens when you use Page Number building blocks associated with a particular location rather than current location.