Headers and footers are useful for repeating the same piece of information at the top and/or bottom of each page, such as if you want to have the title of your book at the top of each page, or page numbers.
Word allows you to choose from a range of predesigned styles.
To create a header select the insert tab and then header.
When you have chosen a style, the header or footer will open. You will also see the Header/Footer Ribbon which will give you specific formatting options.
Now you can type into your header or footer and decide how you would like it aligned, if it needs to be on every page etc.
In the same way you can add page numbers. If you want to “Format Page Numbers,” you can use dialogue box, which will allow you to change the number format, add chapter numbers, and choose where it starts from.