Different Odd And Even

Even Page

Inserts a section break and starts the next section on the next even-numbered page. If the section break alls on an even-numbered page, Word leaves the next odd-numbered page blank.
This starts the new section on the next even numbered page. If the section break falls on an even numbered page, Word leaves the next odd-numbered page blank

Odd Page

Inserts a section break and starts the next section on the next odd-numbered page. If the section break falls on an odd-numbered page, Word leaves the next even-numbered page blank.
This starts the new section on the next odd-numbered page. If the section break falls on an odd numbered page then the next even-numbered page is left blank.

To create separate headers and footers for odd and even pages you use the (File > Page Setup) dialog box.

Select (View > Header and Footer)

Display the Page Setup dialog box and select the "Different Odd and Even" checkbox.

Applying the changes to the Document